@article{gatiboni_shober_fiorellino_osmond_mosesso_2025, title={Drawdown of soil phosphorus by crop removal: A meta-analysis of 56 fields with interrupted fertilization}, volume={10}, ISSN={["2471-9625"]}, url={https://doi.org/10.1002/ael2.70007}, DOI={10.1002/ael2.70007}, abstractNote={Abstract Phosphorus (P) is an essential nutrient applied as fertilizer in agricultural fields. However, excessive fertilization leads to P build up in soils, increasing its potential to cause environmental pollution. The objective of this study was to evaluate the average P drawdown rate of 56 sites with drawdown management presented in 14 publications. Soil test P (STP) results were converted to Mehlich‐3 equivalent and resampling analysis was used to compare the annual drawdown rate in fields grouped by four initial STP classes. The STP was reduced by 4.3%–8.2% per year, depending on the initial STP class. It took from 8.4 to 15.9 years to reduce the STP by half. The resulting equations from this meta‐analysis can be used by landowners to estimate the time needed for STP drawdown by cropping without additional P to achieve the desired STP concentration. Core Ideas Cropping without phosphorus (P) fertilization is one of the few options to reduce soil test P (STP). A meta‐analysis of the annual P drawdown rate was performed using 56 sites presented in 14 publications. Fields were grouped into four initial STP classes based on Mehlich‐3 STP equivalent. The STP was reduced from 4.3% to 8.2% per year in fields with high and low initial STP. The time needed to reduce the STP by half varied from 8.4 to 15.9 years depending on the initial STP.}, number={1}, journal={AGRICULTURAL & ENVIRONMENTAL LETTERS}, author={Gatiboni, Luke and Shober, Amy L. and Fiorellino, Nicole and Osmond, Deanna and Mosesso, Lauren R.}, year={2025}, month={Jun} }
 @article{flaten_kleinman_osmond_2024, title={Balancing agriculture and environment: Andrew Sharpley's nutrient, soil, and water management legacy}, volume={2}, ISSN={["1537-2537"]}, DOI={10.1002/jeq2.20547}, abstractNote={AbstractManaging agricultural phosphorus (P) to balance food security and water quality priorities is a massive challenge fraught with uncertainty and competing interests. Throughout his career, Andrew Sharpley addressed this challenge by building our understanding of the fundamental principles and processes that control P behavior in agricultural land, developing tools to assess P losses, and then evaluating and refining nutrient, soil, and water beneficial management practices (BMPs). Together with an exceptionally large and diverse group of collaborators, Sharpley developed, tested, refined, calibrated, and validated management practices and risk assessment tools to develop site‐specific recommendations for the right practices, in the right places, and at the right times. This approach has resonated globally, with the strategic use of BMPs in “critical source areas” widely implemented in an effort to improve the effectiveness of BMPs while reducing implementation costs. Additional contributions to nutrient management include determining environmental thresholds for soil test P and measuring the risk of P loss from different sources of P (e.g., various manures and commercial fertilizers). Sharpley's work was also distinctly realistic, ensuring that strategies for mitigating P loss were critically evaluated so that not only were the benefits highlighted, but also that trade‐offs were measured. Nowhere is this better illustrated than with trade‐offs in particulate P loss and dissolved P loss with conservation tillage. This review summarizes Sharpley's enormous contributions to our knowledge of agricultural P stewardship as well as his model of collaborative, multi‐disciplinary leadership, helping the world to maintain agricultural productivity and protect water quality.}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Flaten, D. N. and Kleinman, P. J. A. and Osmond, D. L.}, year={2024}, month={Feb} }
 @article{lyons_arnall_ashford-kornburger_brouder_christian_dobermann_haefele_haegele_helmers_jin_et al._2024, title={Field trial guidelines for evaluating enhanced efficiency fertilizers}, volume={10}, ISSN={["1435-0661"]}, DOI={10.1002/saj2.20787}, abstractNote={Abstract There are many fertilizer additives and alternatives that aim to increase plant nutrient use efficiency and reduce nutrient losses to the environment, here referred to collectively as enhanced efficiency fertilizers (EEFs). However, there is often insufficient published scientific field trial results across a variety of locations, climates, soils, cropping systems, and management scenarios to prove their efficacy and conditions for use. Guidelines for common minimum datasets and data stewardship in evaluating the agronomic performance and environmental impact of EEFs are needed for researchers to follow. Such guidelines will improve hypothesis testing centered on product efficacy and provide producers with guidance on how these technologies function and perform when integrated with other management practices within the 4R Nutrient Stewardship Framework. A scientific committee was formed to develop a set of protocol guidelines for evaluating EEFs in replicated, plot‐based field trials on an international scale. The guidelines are composed of experimental design and core metadata, crop and soil analyses, environmental loss measurements, and data stewardship, and include both recommended and required components to allow for flexibility and adaptability depending on the trial location, objectives, infrastructure capacity, product type, and depth of understanding of the potential EEF efficacy. This approach will ensure consistency and compatibility in experimental design and data collection to support data integration, analysis, and reuse leading to large‐scale impact and end‐user confidence.}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Lyons, Sarah E. and Arnall, D. Brian and Ashford-Kornburger, Dana and Brouder, Sylvie M. and Christian, Erik and Dobermann, Achim and Haefele, Stephan M. and Haegele, Jason and Helmers, Matthew J. and Jin, Virginia L. and et al.}, year={2024}, month={Oct} }
 @article{slaton_pearce_gatiboni_osmond_bolster_miquez_clark_dhillon_farmaha_kaiser_et al._2024, title={Models and sufficiency interpretation for estimating critical soil test values for the Fertilizer Recommendation Support Tool}, volume={6}, ISSN={["1435-0661"]}, url={https://doi.org/10.1002/saj2.20704}, DOI={10.1002/saj2.20704}, abstractNote={Abstract Soil test correlation determines whether a soil test can be used to predict the need for fertilization based on the critical soil test value (CSTV). Our objectives were to compare the CSTV estimated from five combinations of correlation models and yield sufficiency interpretations and to select one method for soil test correlation performed with the Fertilizer Recommendation Support Tool (FRST). Four models were fit to three datasets with strong (Mehlich‐1 K), moderate (Mehlich‐3 K), or weak (Olsen P) correlations between soil test P or K and crop relative yield. We tested the arcsine‐log calibration curve (ALCC), exponential (EXP), linear plateau (LP), and quadratic plateau (QP) models. The CSTV was defined as 95% of the maximum predicted yield for the ALCC and EXP methods, the join point for LP, and both the join point and 95% of the maximum for the QP providing five CSTV predictions. The five CSTVs ranged from 46 to 66 mg kg −1 for the Mehlich‐1 K dataset, 115 to 165 mg kg −1 for the Mehlich‐3 K dataset, and 7 to 16 mg kg −1 for the Olsen P dataset. Ten pairwise comparisons showed the estimated CSTV was numerically and sometimes statistically influenced by the model and sufficiency level interpretation. Despite differences among CSTVs, the frequency of significant yield responses above and below the predicted CSTV was generally comparable among the methods, with false‐negative errors occurring at 0%–18% of sites for a given dataset. The QP model with a CSTV at 95% of the predicted maximum was selected as the modeling approach for FRST.}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Slaton, N. A. and Pearce, A. and Gatiboni, L. and Osmond, D. and Bolster, C. and Miquez, F. and Clark, J. and Dhillon, J. and Farmaha, B. and Kaiser, D. and et al.}, year={2024}, month={Jun} }
 @article{macrae_kleinman_osmond_shober_nelson_2024, title={The importance of consensus science to managing phosphorus in the environment: SERA-17 and the legacy of Andrew Sharpley}, volume={2}, ISSN={["1537-2537"]}, DOI={10.1002/jeq2.20546}, abstractNote={AbstractPhosphorus (P) loss from agricultural systems to surface waters, and ultimately, eutrophication, presents a wicked problem requiring transdisciplinary solutions. The mission of SERA‐17 (Southern Extension and Research Advisory Information Exchange Group‐17) has been to address this problem by developing “Innovative Solutions to Minimize Phosphorus Losses from Agriculture.” Over the course of his career, Dr. Andrew Sharpley demonstrated a rare ability to collaboratively achieve consensus around issues related to the science and management of P. The SERA‐17 organization served as the central community of experts and stakeholders where that consensus was built and applied. The consensus‐based approach, demonstrated by Sharpley and at the core of the SERA‐17 organization, was routinely applied to key areas of P science to produce applied outcomes that have been readily adopted: advance foundational science to resolve knowledge gaps and to promote innovation; promote consistency in methods to facilitate comprehensive investigations and conclusions across a diversity of systems; engage diverse stakeholders to prioritize research, and ultimately, ensure that outcomes reflect a plurality of perspectives; and deliver pragmatic solutions that reflect the best information available at a particular time. We review the history of SERA‐17 in delivering new science and management recommendations for P, with an eye to elucidating Sharpley's role and legacy in this process.}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Macrae, Merrin L. and Kleinman, Peter J. A. and Osmond, Deanna and Shober, Amy and Nelson, Nathan}, year={2024}, month={Feb} }
 @article{roper_osmond_heitman_2024, title={Wheat cover crop has minimal effect on physical soil properties in the North Carolina Piedmont}, volume={7}, ISSN={["1435-0645"]}, DOI={10.1002/agj2.21634}, abstractNote={Abstract Environmental awareness about soil and water conservation in agroecosystems has shifted behaviors toward favoring conservation practices in agricultural management. Interest in conservation tillage and cover cropping has increased, but some regions encounter major challenges with adjusting management to accommodate these practices while optimizing crop production. In an Ultisol in the North Carolina Piedmont, a long‐term corn ( Zea mays ) and soybean ( Glycine max ) rotation with tillage intensities ranging from no‐till to moldboard plowing in a randomized complete block design was used to assess changes in physical soil properties after introducing wheat ( Triticum aestivum ) as a winter cover crop. Cover crop biomass was measured along with volumetric water content (VWC) and bulk density (BD) at 0–15 cm, water retention (WR), water‐stable aggregation (WSA), and soil organic carbon (SOC) at 0–7.5 cm, and penetration resistance (PR) at 0–45 cm. No differences in VWC or WR could be solely attributed to cover cropping, but no‐till with cover cropping had the highest macroporosity where there was no vehicle traffic. Vehicle traffic had a stronger effect on soil compaction (BD and PR) than cover cropping regardless of tillage. Conservation tillage increased WSA and SOC when compared to plow tillage, but three seasons of a wheat cover crop did not significantly change these properties, possibly because wheat produced low biomass each year (750–1900 kg ha −1 ). Wheat had minimal effect on physical soil properties in the short term, and potential for improvement with long‐term optimal cover crop management in this region requires further assessment.}, journal={AGRONOMY JOURNAL}, author={Roper, Wayne R. and Osmond, Deanna L. and Heitman, Joshua L.}, year={2024}, month={Jul} }
 @article{osmond_kleinman_coale_nelson_bolster_mcgrath_2024, title={A short history of the phosphorus index and Andrew Sharpley's contributions from inception through development and implementation}, volume={1}, ISSN={["1537-2537"]}, DOI={10.1002/jeq2.20535}, abstractNote={AbstractIn the 1980s, growing recognition of agricultural phosphorus (P) sources to surface water eutrophication led to scrutiny of animal feeding operations. In 1990, the USDA‐Natural Resources Conservation Service (NRCS) invited prominent scientists to find a solution. It was at an initial meeting that Dr. Andrew Sharpley suggested that P assessment could be modeled after the Universal Soil Loss Equation, where a matrix of factors influencing P loss would be associated with farm nutrient management recommendations. After codifying the P assessment into the USDA‐NRCS 590 Nutrient Management Standard some 10 years later, 48 states chose to develop their own P Index. Sharpley, working with many others, helped develop several state P Indices. In 2000, Sharpley secured funding from the USDA‐Agricultural Research Service to support the National P Research Project, which conducted in‐field P runoff assessments using standardized rainfall simulated studies across 20 states; this allowed individual trials to be aggregated for agroecological regions that were then incorporated into specific state P Indices. Eventually, comparison of P Indices across state boundaries led to a white paper at the behest of USDA‐NRCS that resulted in three regional projects evaluating modeling approaches to support or replace P Indices. Sharpley's national umbrella project pointed to shortcomings in water quality models, such as APEX or TBET, as a replacement for state P Indices, which remain a key part of the USDA‐590 standard. As a selfless leader, capable of attracting and assembling diverse, productive interdisciplinary teams, Sharpley was essential to the inception, development, and implementation of the P Index.}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Osmond, Deanna L. and Kleinman, Peter J. A. and Coale, Frank and Nelson, Nathan O. and Bolster, Carl H. and Mcgrath, Josh}, year={2024}, month={Jan} }
 @article{lyons_clark_osmond_parvej_pearce_slaton_spargo_2023, title={Current status of US soil test phosphorus and potassium recommendations and analytical methods}, volume={4}, ISSN={["1435-0661"]}, DOI={10.1002/saj2.20536}, abstractNote={AbstractSoil testing is the foundation of fertilizer recommendations in the United States. Fertilizer recommendations have primarily been developed by land‐grant universities with limited coordination among programs. The individual state approach to develop fertilizer recommendations has resulted in discrepancies in recommended soil sampling protocols, soil analysis methods, and fertilizer recommendations at similar soil nutrient levels. A national survey was developed to summarize the status of soil testing and fertility work in the United States to inform future collaborative efforts among states and regions and identify opportunities to harmonize recommendation guidelines. Topics included relevant funding, multi‐state collaborations, state soil‐test recommendations and related data, fertilization philosophies, and analytical and soil sampling methods. Responses from 48 states and Puerto Rico showed inconsistencies across state boundaries in every category. The number of faculty full‐time equivalents working in soil fertility now averages 1.3 per state, a 21.5% decrease every 10 years since the 1950s. Land‐grant university soil‐test‐based phosphorus (P) and potassium (K) recommendation philosophies were categorized as Sufficiency (37%), Build and Maintain (19%), hybrid (20%), or multiple philosophies for which recommendations are provided (20%). Respondents in two states did not know the recommendation philosophy (4%). Fertilizer‐P and K recommendations for corn (Zea mays L.) were based on eight different extractants with differences across and within regions. While there have been some successful regional efforts in the past, additional multi‐state collaborative efforts are needed to identify research gaps and develop comprehensive strategies to update soil‐test correlation and calibration data to address modern agronomic, economic, and environmental concerns.}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Lyons, Sarah E. and Clark, Jason D. and Osmond, Deanna L. and Parvej, M. D. Rasel and Pearce, Austin W. and Slaton, Nathan A. and Spargo, John T.}, year={2023}, month={Apr} }
 @article{chen_carley_munoz-carpena_ferruzzi_yuan_henry_blankinship_veith_breckels_fox_et al._2023, title={Incorporating the benefits of vegetative filter strips into risk assessment and risk management of pesticides}, volume={9}, ISSN={["1551-3793"]}, url={https://doi.org/10.1002/ieam.4824}, DOI={10.1002/ieam.4824}, abstractNote={AbstractThe pesticide registration process in North America, including the USA and Canada, involves conducting a risk assessment based on relatively conservative modeling to predict pesticide concentrations in receiving waterbodies. The modeling framework does not consider some commonly adopted best management practices that can reduce the amount of pesticide that may reach a waterbody, such as vegetative filter strips (VFS). Currently, VFS are being used by growers as an effective way to reduce off‐site movement of pesticides, and they are being required or recommended on pesticide labels as a mitigation measure. Given the regulatory need, a pair of multistakeholder workshops were held in Raleigh, North Carolina, to discuss how to incorporate VFS into pesticide risk assessment and risk management procedures within the North American regulatory framework. Because the risk assessment process depends heavily on modeling, one key question was how to quantitatively incorporate VFS into the existing modeling approach. Key outcomes from the workshops include the following: VFS have proven effective in reducing pesticide runoff to surface waterbodies when properly located, designed, implemented, and maintained; Vegetative Filter Strip Modeling System (VFSMOD), a science‐based and widely validated mechanistic model, is suitable for further vetting as a quantitative simulation approach to pesticide mitigation with VFS in current regulatory settings; and VFSMOD parametrization rules need to be developed for the North American aquatic exposure assessment. Integr Environ Assess Manag 2024;20:454–464. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).}, journal={INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT}, author={Chen, Huajin and Carley, Danesha Seth and Munoz-Carpena, Rafael and Ferruzzi, Giulio and Yuan, Yongping and Henry, Eric and Blankinship, Amy and Veith, Tamie L. and Breckels, Ross and Fox, Garey and et al.}, year={2023}, month={Sep} }
 @article{mathers_heitman_huseth_locke_osmond_woodley_2023, title={No-till imparts yield stability and greater cumulative yield under variable weather conditions in the southeastern USA piedmont}, volume={292}, ISSN={0378-4290}, url={http://dx.doi.org/10.1016/j.fcr.2023.108811}, DOI={10.1016/j.fcr.2023.108811}, abstractNote={With projected increases in global temperatures and changes in regional climate, understanding the impact of soil management choices on yield stability is critical for farmer decision-making and agricultural resiliency. No-till and conservation tillage have had variable yield effects depending on crop and location, requiring long-term system-specific studies to gauge potential benefits. Yield and weather data from a 28-year tillage study in the southeastern U.S. piedmont region were analyzed to determine the effect of various conservation tillage practices on maize and soybean productivity and stability under a variety of growth conditions. Growing seasons were grouped by soil moisture and temperature during crop growth stages, and mean crop yields and yield coefficient of variation for the tillage treatments were calculated within the year clusters. Probability density estimates were also used to predict the likelihood of obtaining yields at low and high percentiles. No-till and conservation tillage increased maize yields 42–93% and no-till decreased coefficient of variation of maize yields when soil moisture was low by 10–32%, but had a less pronounced effect on soybean yields. However, the probability of reaching the 90th yield percentile was greater in no-till than conventional tillage in both maize and soybean, by 15% and 10%, respectively. Yield differentiation occurred early in the study, before there was likely substantial differentiation of soil properties from tillage treatments. Previous reports from the site have likewise indicated little differentiation in soil health between tillage systems over the life of the study. Results suggest that surface residue management may be an important driver of system performance, possibly more so than overall soil health.}, journal={Field Crops Research}, publisher={Elsevier BV}, author={Mathers, Cara and Heitman, Joshua and Huseth, Anders and Locke, Anna and Osmond, Deanna and Woodley, Alexander}, year={2023}, month={Mar}, pages={108811} }
 @article{tiecher_gatiboni_osmond_hardy_2023, title={Soil sampling depth effect on critical soil test values of phosphorus for conservation agriculture}, volume={9}, ISSN={["2374-3832"]}, url={https://doi.org/10.1002/cft2.20251}, DOI={10.1002/cft2.20251}, abstractNote={AbstractThe critical soil test value (CSTV) of phosphorus (P) is the threshold where it is possible to obtain 95–100% of the maximum crop yield. Although the P buildup in the topsoil of conservation tillage may affect this threshold, the effect of soil sampling depth on CSTV value has not been determined for conservation tillage in the southern United States. The objective of this study was to evaluate CSTV of P using different soil layers from two long‐term experiments managed under varying P rates, planted to corn (Zea mays L.)/soybean [Glycine max (L.) Merr.] rotation under minimum tillage (Tidewater) or no‐tillage (Piedmont) in North Carolina. Soil samples were taken from depths of 0–2, 2–4, 4–8, and 8–12 inches. The CSTV for different soil layers was calculated using a quadratic‐plateau model with Mehlich‐3 P and relative yield of soybean and corn (2021–2022). The CSTV decreased as the soil sampling depth increased. The CSTV of P at the Tidewater site was 128, 111, 86, and 74 lb ac−1, and at the Piedmont site was 28, 20, 16, and 15 lb ac−1 for the 0–2, 0–4, 0–8, and 0–12 inches soil layers, respectively. Using multiple sampling layers or deeper layers did not improve the quality of CSTV measurement. The current sampling depths used in North Carolina are appropriate for minimum tillage (0–8 inches) and no tillage (0–4 inches), as similar quality models were obtained using either soil layers in both sites. However, it is important to be cautious when changing the sampling depth, as this affects the CSTV value.}, number={2}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Tiecher, Tales and Gatiboni, Luke and Osmond, Deanna and Hardy, David}, year={2023}, month={Dec} }
 @article{welikhe_williams_king_bos_akland_baffaut_beck_bierer_bosch_brooks_et al._2023, title={Uncertainty in phosphorus fluxes and budgets across the US long-term agroecosystem research network}, volume={6}, ISSN={["1537-2537"]}, DOI={10.1002/jeq2.20485}, abstractNote={AbstractPhosphorus (P) budgets can be useful tools for understanding nutrient cycling and quantifying the effectiveness of nutrient management planning and policies; however, uncertainties in agricultural nutrient budgets are not often quantitatively assessed. The objective of this study was to evaluate uncertainty in P fluxes (fertilizer/manure application, atmospheric deposition, irrigation, crop removal, surface runoff, and leachate) and the propagation of these uncertainties to annual P budgets. Data from 56 cropping systems in the P‐FLUX database, which spans diverse rotations and landscapes across the United States and Canada, were evaluated. Results showed that across cropping systems, average annual P budget was 22.4 kg P ha−1 (range = −32.7 to 340.6 kg P ha−1), with an average uncertainty of 13.1 kg P ha−1 (range = 1.0–87.1 kg P ha−1). Fertilizer/manure application and crop removal were the largest P fluxes across cropping systems and, as a result, accounted for the largest fraction of uncertainty in annual budgets (61% and 37%, respectively). Remaining fluxes individually accounted for <2% of the budget uncertainty. Uncertainties were large enough that determining whether P was increasing, decreasing, or not changing was inconclusive in 39% of the budgets evaluated. Findings indicate that more careful and/or direct measurements of inputs, outputs, and stocks are needed. Recommendations for minimizing uncertainty in P budgets based on the results of the study were developed. Quantifying, communicating, and constraining uncertainty in budgets among production systems and multiple geographies is critical for engaging stakeholders, developing local and national strategies for P reduction, and informing policy.}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Welikhe, Pauline and Williams, Mark R. and King, Kevin and Bos, Janae and Akland, Mark and Baffaut, Claire and Beck, E. Glynn and Bierer, Andrew and Bosch, David D. and Brooks, Erin S. and et al.}, year={2023}, month={Jun} }
 @article{bolster_correndo_pearce_spargo_slaton_osmond_2022, title={A spreadsheet for determining critical soil test values using the modified arcsine-log calibration curve}, volume={12}, ISSN={["1435-0661"]}, DOI={10.1002/saj2.20498}, abstractNote={AbstractSoil test correlation data are often used to identify a critical soil test value (CSTV), above which crop response to added fertilizer is not expected. Oftentimes, models are used to determine the CSTV from soil test correlation data, yet most commonly used models have inherent assumptions that may not be valid for these data. The arcsine‐log calibration curve (ALCC) was developed in response to the statistical limitations of other commonly used models. A modified ALCC model using standardized major axis regression further improves this model's applicability to soil test correlation data. Here, we describe a Microsoft Excel spreadsheet for calculating CSTV from soil test correlation data using the modified ALCC model. The spreadsheet is available for download providing an accessible and easy‐to‐use tool for those who would like to use this method but who lack the experience with more sophisticated coding programs. The spreadsheet is available for download at http://www.ars.usda.gov/ALCC.}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Bolster, Carl H. and Correndo, Adrian A. and Pearce, Austin W. and Spargo, John T. and Slaton, Nathan A. and Osmond, Deanna L.}, year={2022}, month={Dec} }
 @article{kleinman_osmond_christianson_flaten_ippolito_jarvie_kaye_king_leytem_mcgrath_et al._2022, title={Addressing conservation practice limitations and trade-offs for reducing phosphorus loss from agricultural fields}, volume={7}, ISSN={["2471-9625"]}, DOI={10.1002/ael2.20084}, abstractNote={AbstractConservation practices that reduce nutrient and soil loss from agricultural lands to water are fundamental to watershed management programs. Avoiding trade‐offs of conservation practices is essential to the successful mitigation of watershed phosphorus (P) losses. We review documented trade‐offs associated with conservation practices, particularly those practices that are intended to control and trap P from agricultural sources. A regular theme is the trade‐off between controlling P loss linked to sediment while increasing dissolved P losses (no‐till, cover crops, vegetated buffers, constructed wetlands, sediment control basins). A variety of factors influence the degree to which these trade‐offs occur, complicated by their interaction and uncertainties associated with climate change. However, acknowledging these trade‐offs and anticipating their contribution to watershed outcomes are essential to the sustainability of conservation systems.}, number={2}, journal={AGRICULTURAL & ENVIRONMENTAL LETTERS}, author={Kleinman, Peter J. A. and Osmond, Deanna L. and Christianson, Laura E. and Flaten, Don N. and Ippolito, James A. and Jarvie, Helen P. and Kaye, Jason P. and King, Kevin W. and Leytem, April B. and McGrath, Joshua M. and et al.}, year={2022} }
 @article{respess_austin_gatiboni_osmond_2022, title={Assessing the Agricultural Conservation Planning Framework toolbox in a Southern Piedmont landscape of the United States}, volume={77}, ISSN={["1941-3300"]}, DOI={10.2489/jswc.2022.00138}, abstractNote={The Agricultural Conservation Planning Framework (ACPF) is a geospatial decision support tool that was developed and is used in many areas of the Midwest of the United States to help with the prioritization and placement of conservation practices within agricultural watersheds. We evaluated the utility and extensibility of ACPF in two US Geological Survey 12-digit scale hydrologic units in the Southern Piedmont of North Carolina. The Southern Piedmont consists of less row crop agriculture and more pasture systems than the Midwest and has generally lower pollutant loads. Also, agricultural fields are comparatively smaller, irregularly shaped, and more sparsely distributed. For this study, local conservation experts were interviewed about conservation practices and their appropriate locations in the landscape. Interviewees demonstrated an extensive working knowledge of the land and producers on over 90% of the farmland. Many of the conservation practices identified by the local experts were “soil health” practices, such as cover crops or nutrient management, and are assumed in use before running ACPF. Results revealed that many of the conservation practices output by ACPF were not identified by the local experts in the Southern Piedmont watersheds due to their limited use in pasture conservation, conservation priorities, and landscape characteristics. Row crop agriculture was sparsely distributed in each study watershed and comprised less than 2% of the total catchment area. Contour buffer strips and grassed waterways were the conservation practices most identified by ACPF and were sited in 75% of cropped fields. A greater number of crop-related conservation practices (48 versus 15) were identified by ACPF than by local experts; however 80% of the conservation practices identified by the experts were outside the scope of ACPF and were mainly nutrient management or soil health practices. To evaluate ACPF for broader utility in the Southern Piedmont, alternative interpretations for existing outputs were considered: (1) ACPF “proxies” were identified to compare locally accepted practices with ACPF outputs that perform a similar function (e.g., strip cropping rather than contour buffer strips) and, (2) placing locally used conservation practices (e.g., exclusion fencing) based on existing ACPF data layers (hydrologically enforced flow paths). Alternative uses and interpretations surrounding ACPF outputs and data layers may provide opportunities for conservation planning outside the scope and intended use of ACPF in the Southern Piedmont.}, number={5}, journal={JOURNAL OF SOIL AND WATER CONSERVATION}, author={Respess, Z. M. and Austin, R. and Gatiboni, L. and Osmond, D.}, year={2022}, pages={441–449} }
 @article{morales_gatiboni_osmond_vann_kulesza_crozier_hardy_2023, title={Critical soil test values of phosphorus and potassium for soybean and corn in three long-term trials in North Carolina}, volume={1}, ISSN={["1435-0661"]}, url={https://doi.org/10.1002/saj2.20491}, DOI={10.1002/saj2.20491}, abstractNote={AbstractSoil test correlation is continuously necessary to affirm critical soil test values (CSTV) for specific nutrients, as changes in crop management and development of new plant varieties may change CSTVs. The objective of this study was to determine the CSTVs of phosphorus (P) and potassium (K) for soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) using three long‐term trials in North Carolina. Soybean was cultivated in 2020 and corn in 2021 in three long‐term trials established on research stations located in the Tidewater, Coastal Plain, and Piedmont regions of NC. In each trial, up to five rates of P (0–88.2 kg P ha−1) and K (0–186.8 kg K ha−1) were applied annually at planting. Soil and tissue samples were analyzed and yield measured. There was yield response to P in all site‐years. The average CSTVs of P for corn and soybean were 51, 66, and 14 mg kg−1 for the sites at Tidewater, Coastal Plain, and Piedmont regions. The CSTV of P for Piedmont (14 mg kg−1) differs greatly from the current recommendation for NC (52 mg kg−1). The response to K fertilization was observed only in three site‐years and the CSTVs varied from 49 to 93 mg kg−1, while the current recommendation is setting the CSTV of K at 85 mg kg−1. These results indicate it is necessary to develop further studies of soil test correlation for P and K in North Carolina to better estimate the CSTVs for the state.}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Morales, Nelida Agramont and Gatiboni, Luke and Osmond, Deanna and Vann, Rachel and Kulesza, Stephanie and Crozier, Carl and Hardy, David}, year={2023}, month={Jan} }
 @article{pearce_slaton_lyons_bolster_bruulsema_grove_jones_mcgrath_miguez_nelson_et al._2022, title={Defining relative yield for soil test correlation and calibration trials in the fertilizer recommendation support tool}, volume={8}, ISSN={["1435-0661"]}, DOI={10.1002/saj2.20450}, abstractNote={AbstractThe Fertilizer Recommendation Support Tool (FRST) will perform correlations between soil nutrient concentrations and crop response to fertilization from user‐selected datasets in the FRST national database. Yield response for the nutrient of interest in a particular site‐year is presented as relative yield (RY), a ratio of unfertilized yield to the maximum attainable yield (A). Several methods exist in the literature for estimating A and calculating RY but the effect of method choice on soil test correlation outcomes is undocumented. We used six published methods to calculate RY from site‐year yield data for five published correlation datasets, and fit a generalized linear plateau (LP) model to each. The critical soil test value (at the LP join point) and RY intercept coefficients were not significantly affected by RY method for any of the datasets, and RY plateau was significantly affected by method for only one dataset. The top options after robust group discussions were the so‐called MAX and FITMAX methods. We selected the MAX method, which defines A as the numerically highest treatment yield mean, as the most appropriate method for FRST because MAX represents maximal yield in responsive sites, is inclusive of trial data having a range of treatment numbers, limits RY to 100% (which allows options for transforming data), and is simpler to implement than FITMAX, which requires a decision tree to calculate RY for diverse trials.}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Pearce, Austin W. and Slaton, Nathan A. and Lyons, Sarah E. and Bolster, Carl H. and Bruulsema, Tom W. and Grove, John H. and Jones, John D. and McGrath, Josh M. and Miguez, Fernando E. and Nelson, Nathan O. and et al.}, year={2022}, month={Aug} }
 @article{williams_welikhe_bos_king_akland_augustine_baffaut_beck_bierer_bosch_et al._2022, title={P-FLUX: A phosphorus budget dataset spanning diverse agricultural production systems in the United States and Canada}, volume={4}, ISSN={["1537-2537"]}, DOI={10.1002/jeq2.20351}, abstractNote={AbstractQuantifying spatial and temporal fluxes of phosphorus (P) within and among agricultural production systems is critical for sustaining agricultural production while minimizing environmental impacts. To better understand P fluxes in agricultural landscapes, P‐FLUX, a detailed and harmonized dataset of P inputs, outputs, and budgets, as well as estimated uncertainties for each P flux and budget, was developed. Data were collected from 24 research sites and 61 production systems through the Long‐term Agroecosystem Research (LTAR) network and partner organizations spanning 22 U.S. states and 2 Canadian provinces. The objectives of this paper are to (a) present and provide a description of the P‐FLUX dataset, (b) provide summary analyses of the agricultural production systems included in the dataset and the variability in P inputs and outputs across systems, and (c) provide details for accessing the dataset, dataset limitations, and an example of future use. P‐FLUX includes information on select site characteristics (area, soil series), crop rotation, P inputs (P application rate, source, timing, placement, P in irrigation water, atmospheric deposition), P outputs (crop removal, hydrologic losses), P budgets (agronomic budget, overall budget), uncertainties associated with each flux and budget, and data sources. Phosphorus fluxes and budgets vary across agricultural production systems and are useful resources to improve P use efficiency and develop management strategies to mitigate environmental impacts of agricultural systems. P‐FLUX is available for download through the USDA Ag Data Commons (https://doi.org/10.15482/USDA.ADC/1523365).}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Williams, M. R. and Welikhe, P. and Bos, J. and King, K. and Akland, M. and Augustine, D. and Baffaut, C. and Beck, E. G. and Bierer, A. and Bosch, D. D. and et al.}, year={2022}, month={Apr} }
 @article{correndo_pearce_bolster_spargo_osmond_ciampitti_2023, title={The soiltestcorr R package: An accessible framework for reproducible correlation analysis of crop yield and soil test data}, volume={21}, ISSN={["2352-7110"]}, DOI={10.1016/j.softx.2022.101275}, abstractNote={The soiltestcorr R package is an open-source software designed to enable accessible and reproducible computation of correlation analyses between crop yield response to fertilization and soil test values. The package compiles a series of functions for analyzing soil test correlation data: (i) Cate & Nelson data partitioning procedure (graphical and statistical versions), (ii) nonlinear regression analysis (linear-plateau, quadratic-plateau, and Mitscherlich-type exponential models), and (iii) the modified arcsine-log calibration curve. The soiltestcorr enables users to correlate crop response to soil nutrient availability and estimate a critical soil test value and visualize results with ggplot without requiring advanced R programming skills. Finally, a web application that facilitates the use of the package is also offered for users with no background in R programming.}, journal={SOFTWAREX}, author={Correndo, Adrian A. and Pearce, Austin and Bolster, Carl H. and Spargo, John T. and Osmond, Deanna and Ciampitti, Ignacio A.}, year={2023}, month={Feb} }
 @article{'connell_osmond_2022, title={Why soil testing is not enough: A mixed methods study of farmer nutrient management decision-making among US producers}, volume={314}, ISSN={["1095-8630"]}, DOI={10.1016/j.jenvman.2022.115027}, abstractNote={Understanding farmers' nutrient management decision-making is critical to minimizing nutrient loss to water resources. This research examines farmer decision-making in the United States surrounding nutrients (primarily nitrogen and phosphorus) and water quality among 105 farmers in Missouri, North Carolina, and Ohio. Data were collected between 2015 and 2016 using a mixed-methods approach of in-person farmer interviews and accompanying quantitative surveys with demographic and Likert ranking questions. This work presents findings regarding 1) how farmers made decisions, 2) who and what they consult with when making decisions, and 3) how their views on local water quality and regional pollution impact their choices. Farmers reported many resources for information when making nutrient management decisions including yield data, market prices, weather, product availability, prior experience, risk management/avoidance, university research reports, soil and tissue sampling, and social networks. Location also shaped how farmers made nutrient management decisions both because of differences in the structure and types of professional and informal support available to farmers as well as how individuals perceived the severity of local water problems. Younger farmers saw more room for improvement in their nutrient management practices while older farmers were more likely to be satisfied with current practices and decisions. Ultimately, our findings suggest we need to tailor programs and education to regional economic, social norm, and environmental contexts with recognition that past experiences and long-term knowledge shape how farmers receive new interventions. Constructing multifaceted approaches to address these diverse conditions is a critical step in improving water quality when it comes to nutrient management choices.}, journal={JOURNAL OF ENVIRONMENTAL MANAGEMENT}, author={'Connell, Caela and Osmond, D. L.}, year={2022}, month={Jul} }
 @article{lyons_arthur_slaton_pearce_spargo_osmond_kleinman_2021, title={Development of a soil test correlation and calibration database for the USA}, volume={6}, ISSN={["2471-9625"]}, DOI={10.1002/ael2.20058}, abstractNote={AbstractAs part of the Fertilizer Recommendation Support Tool (FRST) project, the FRST database was developed to consolidate and preserve U.S. soil test correlation and calibration data. Legacy phosphorus (P) and potassium (K) soil test data that met a minimum requirement were included in the database. The FRST database initially included over 1,200 individual trials from a range of years, cropping systems, geographic regions, and management practices. The FRST database is being migrated from a Microsoft Excel spreadsheet to a relational database format housed within the USDA‐ARS Agricultural Collaborative Research Outcomes System (AgCROS) to be accessed via the online FRST decision support tool. Data will be continually added to the FRST database through an online submission form following peer review by the FRST team. The FRST database and associated decision support tool will aid researchers, extension associates, consultants, and farmers in improving fertilizer recommendations for crops across the United States.}, number={4}, journal={AGRICULTURAL & ENVIRONMENTAL LETTERS}, author={Lyons, Sarah E. and Arthur, Dan K. and Slaton, Nathan A. and Pearce, Austin W. and Spargo, John T. and Osmond, Deanna L. and Kleinman, Peter J. A.}, year={2021} }
 @article{slaton_lyons_osmond_brouder_culman_drescher_gatiboni_hoben_kleinman_mcgrath_et al._2021, title={Minimum dataset and metadata guidelines for soil-test correlation and calibration research}, volume={11}, ISSN={["1435-0661"]}, url={https://doi.org/10.1002/saj2.20338}, DOI={10.1002/saj2.20338}, abstractNote={AbstractSoil‐test correlation and calibration data are essential to modern agriculture, and their continued relevance is underscored by the expansion of precision farming and the persistence of sustainable soil management priorities. In support of transparent, science‐based fertilizer recommendations, we seek to establish a core set of required and recommended information for soil‐test P and K correlation and calibration studies, a minimum dataset, building on previous research. The Fertilizer Recommendation Support Tool (FRST) project team and collaborators are developing a national database that will support a soil‐test‐based nutrient management decision aid tool. The FRST team includes over 80 scientists from 37 land‐grant universities, two state universities, one private university, three federal agencies, two private not‐for‐profit organizations, and one state department of agriculture. The minimum dataset committee developed and vetted a robust set of factors fo minimum dataset consideration that includes information on soil sample collection and processing, soil chemical and physical properties, experimental design and statistical analyses, and metadata about the trial, production system, and field management. The minimum dataset provides guidelines for essential information to meet the primary objective of knowledge synthesis, including meta‐analysis and systemic reviews, but permits researchers the flexibility to satisfy local, state, and regional objectives. Ultimately, this consensus‐driven effort seeks to establish a standard that ensures the maximum utility and impact of modern correlation and calibration studies for developing crop nutrition recommendations that improve productivity and profitability for the crop producer, while reducing environmental impacts of nutrient losses.}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, publisher={Wiley}, author={Slaton, Nathan A. and Lyons, Sarah E. and Osmond, Deanna L. and Brouder, Sylvie M. and Culman, Steve W. and Drescher, Gerson and Gatiboni, Luciano C. and Hoben, John and Kleinman, Peter J. A. and McGrath, Joshua M. and et al.}, year={2021}, month={Nov} }
 @article{duncan_respess_ryan_austin_royer_osmond_kleinman_2021, title={The Agricultural Conservation Planning Framework: Opportunities and challenges in the eastern United States}, volume={6}, ISSN={["2471-9625"]}, DOI={10.1002/ael2.20054}, abstractNote={AbstractThe Agriculture Conservation Planning Framework (ACPF) applies high‐spatial resolution soils and topographic data, now available for many areas of the United States, to precisely locate opportunities for the placement of conservation practices in agricultural watersheds. Application of the ACPF, developed in midwestern landscapes, to watersheds in the eastern United States represents both opportunity and challenge to conservation planning. Based on experience in applying ACPF to eight watersheds in the eastern United States, from Vermont to North Carolina, we assess the toolbox's application in the eastern United States through the lens of strengths, weaknesses, opportunities, and threats (SWOT) analysis framework. We see a great future for the ACPF, but its adoption and utility require interaction with scientists and conservation planners familiar with the region to avoid misapplication and ensure appropriate adaptation and interpretation.}, number={3}, journal={AGRICULTURAL & ENVIRONMENTAL LETTERS}, author={Duncan, Jonathan M. and Respess, Zachary and Ryan, William and Austin, Robert and Royer, Matthew and Osmond, Deanna and Kleinman, Peter}, year={2021} }
 @article{zhang_antonangelo_grove_osmond_slaton_alford_florence_huluka_hardy_lessl_et al._2021, title={Variation in soil-test-based phosphorus and potassium rate recommendations across the southern USA}, volume={6}, ISSN={["1435-0661"]}, DOI={10.1002/saj2.20280}, abstractNote={AbstractThirteen states associated with the Southern Extension and Research Activities Information Exchange Group‐6 (SERA‐IEG‐6) agreed to share their soil test based P and K rate recommendations for nine major crops. The objectives were to compare fertilizer P and K rate recommendations, to look for opportunities to rationalize similar recommendations across state lines, and to examine challenges to the development of a cooperative regional approach to P and K recommendations. Mehlich‐3 (eight states), Mehlich‐1 (five states), or Lancaster (one state) extractions were the basis of plant available soil P (STP) and K (STK) assessment. Fertilizer recommendation philosophies (sufficiency, build and maintain, and/or hybrid) variation among the states might be the main reason behind such discrepancies. Although a few similarities in P and K rate recommendations were found, the different philosophies, numerical presentations, and extraction procedures drove important recommendation differences. Widespread adoption of the Mehlich‐3 extraction procedure has not reduced variation in fertilizer P and K rate recommendations among the states. Instead, for states using Mehlich 3, soil test critical concentrations ranged from 30 to 75 mg P kg–1 and 60 to 175 mg K kg–1 for corn (Zea mays L.) grain and warm‐season grass hay production. The adoption of uniform soil testing terminology, sample collection guidelines, extraction methods, and interpretations across common physiographic regions, soils, and state lines remains a challenge. Differences arise because of the different soil orders and properties, climate conditions, and resulting crop responses to added P and K fertilizers. Such differences in soil‐test‐based fertilizer P and K recommendations are state specific and highlight needs to examine the soil testing and recommendation process, make soil test results end‐user friendly, and, when appropriate, standardize fundamental information used in the soil testing guidelines.}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Zhang, Hailin and Antonangelo, Joao and Grove, John and Osmond, Deanna and Slaton, Nathan A. and Alford, Shannon and Florence, Robert and Huluka, Gobena and Hardy, David Herring and Lessl, Jason and et al.}, year={2021}, month={Jun} }
 @article{lyons_osmond_slaton_spargo_kleinman_arthur_mcgrath_2020, title={FRST: A national soil testing database to improve fertility recommendations}, volume={5}, ISSN={["2471-9625"]}, DOI={10.1002/ael2.20008}, abstractNote={AbstractSoil testing is an important practice for nutrient management in agricultural production systems. In the United States, soil‐test methods and interpretations vary across state lines, making institutional collaborations challenging and crop fertilization guidelines inconsistent. Uniformity and transparency in P and K soil fertility testing and fertilizer recommendations are needed to enhance end‐user adoption. The Fertilizer Recommendation Support Tool (FRST) project is developing a comprehensive database of P and K correlation–calibration results that can be accessed through an online tool for use in research and fertilizer recommendation development. This collaborative project, which includes over 30 land‐grant universities, the USDA‐ARS, the USDA‐NRCS, and several not‐for‐profit organizations, contains a national survey describing the current status of soil testing, minimum requirements for correlation–calibration data inclusion, and database population and creating FRST as a user‐friendly online decision support tool. The FRST project will provide more consistent, transparent, and science‐based information for crop nutrient recommendations across the United States.}, number={1}, journal={AGRICULTURAL & ENVIRONMENTAL LETTERS}, author={Lyons, Sarah E. and Osmond, Deanna L. and Slaton, Nathan A. and Spargo, John T. and Kleinman, Peter J. A. and Arthur, Dan K. and McGrath, Joshua M.}, year={2020} }
 @article{moriasi_duriancik_sadler_tsegaye_steiner_locke_strickland_osmond_2020, title={Quantifying the impacts of the Conservation Effects Assessment Project watershed assessments: The first fifteen years}, volume={75}, ISSN={["1941-3300"]}, DOI={10.2489/jswc.75.3.57A}, abstractNote={T he United States Department of Agriculture (USDA) spends about US$6 billion each year on agricultural conservation programs to help producers and landowners implement conservation practices (CPs) and systems on their land. In 2003, the USDA Natural Resources Conservation Service (NRCS) entered into partnership with USDA Agricultural Research Service (ARS), USDA National Institute of Food and Agriculture (NIFA), other federal agencies, and many external partners to create the Conservation Effects Assessment Project (CEAP). The goal of CEAP is to quantify the environmental effects of CPs and programs and develop the science base for managing the agricultural landscape for environmental quality (Mausbach and Dedrick 2004; Duriancik et al. 2008). Conservation effects are assessed at national, regional, and watershed scales on cropland, grazing lands, wetlands, and for wildlife. As part of these efforts, CEAP initiated the Watershed Assessment Studies (WAS) component …}, number={3}, journal={JOURNAL OF SOIL AND WATER CONSERVATION}, author={Moriasi, Daniel N. and Duriancik, Lisa F. and Sadler, E. John and Tsegaye, Teferi and Steiner, Jean L. and Locke, Martin A. and Strickland, Timothy C. and Osmond, Deanna L.}, year={2020}, pages={57A–74A} }
 @article{roper_osmond_heitman_2019, title={A Response to "Reanalysis Validates Soil Health Indicator Sensitivity and Correlation with Long-term Crop Yields"}, volume={83}, ISSN={["1435-0661"]}, DOI={10.2136/sssaj2019.06.0198}, abstractNote={We published data showing that current soil health indicator (SHI) assessments do not consistently detect differences in a range of soil management practices implemented in North Carolina soils. Van Es and Karlen reanalyzed our data and asserted that it validates SHI correlation to crop yields and sensitivity to management as measured by the Comprehensive Assessment of Soil Health (CASH). We respond to van Es and Karlen with a more representative analysis of our data showing that individual SHI measurements are not predictive of crop yield from the 30‐yr North Carolina agronomic trial. Regressions for aggregate stability (r2 = 0.07) and P (r2 = 0.18) show that neither SHI sufficiently predicts corn yield for this dataset and show no obvious pattern based on tillage intensity. Relationships between corn (Zea mays L.) yield and most biological SHI had r2 ≤ 0.18, with only soil protein being moderately predictive of corn yield (r2 = 0.45). The CASH index to assess overall soil health by integrating physical, chemical, and biological SHI measurements into a single value of soil health is also not predictive of corn yield in the trial (r2 = 0.12). It is possible that current sampling and analytical procedures for assessing soil health do not consistently detect differences in productivity from soils with regional differences in land and ecological resources. We believe that calibrating SHI assessments to quantifiable agroecological outcomes instead of statistical rankings will reduce bias across regions and create a more inclusive framework for quantifying soil health.}, number={6}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Roper, Wayne R. and Osmond, Deanna L. and Heitman, Joshua L.}, year={2019}, pages={1842–1845} }
 @article{roper_robarge_osmond_heitman_2019, title={Comparing Four Methods of Measuring Soil Organic Matter in North Carolina Soils}, volume={83}, ISSN={["1435-0661"]}, DOI={10.2136/sssaj2018.03.0105}, abstractNote={
Core Ideas
Results of agronomic management effects on SOM are inconsistent among methods.
Correlations among methods of measuring SOM differ depending on soil.
Soil organic matter content should be compared using similar procedures.
Soil organic matter (SOM) provides many beneficial soil ecosystem services for sustainable soil management, but it is unclear how results from different methods of measuring SOM should be compared when making soil management decisions. To compare different methods, we used 84 soil samples from long‐term agronomic trials in the coastal plain, piedmont, and mountain regions of North Carolina. Coastal plain and mountain trials included combinations of tillage and management (conventional vs. organic), whereas piedmont trials were configured to evaluate tillage intensity. The methods used to measure SOM were Walkley‐Black (WB), mass loss on ignition (LOI), automated dry combustion (ADC), and humic matter (HM) colorimetry. Correlations among LOI, WB, and ADC were significant (p < 0.0001) for SOM measured from the total population of soils, but variability due to location implied that HM had no correlation to other methods. For measures of soil organic carbon compared to SOM, the WB results were biased high compared to ADC, and ADC was more strongly correlated to LOI than WB. When using the methods to evaluate the effects of agronomic management on SOM, results varied for different methods and locations. Conservation management did not consistently accumulate more SOM than other soil management practices, and no method consistently differentiated soils based on management. Variation in the composition of SOM measured using conventional methods may be causing discrepancies in reported changes in SOM content over time. To avoid confusion about how agronomic management affects SOM, assessments should limit comparisons to methodologies with similar measurement protocols.}, number={2}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Roper, Wayne R. and Robarge, Wayne P. and Osmond, Deanna L. and Heitman, Joshua L.}, year={2019}, pages={466–474} }
 @article{bolster_baffaut_nelson_osmond_cabrera_ramirez-avila_sharpley_veith_mcfarland_senaviratne_et al._2019, title={Development of PLEAD: A Database Containing Event-based Runoff Phosphorus Loadings from Agricultural Fields}, volume={48}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2018.09.0337}, abstractNote={Computer models are commonly used for predicting risks of runoff P loss from agricultural fields by enabling simulation of various management practices and climatic scenarios. For P loss models to be useful tools, however, they must accurately predict P loss for a wide range of climatic, physiographic, and land management conditions. A complicating factor in developing and evaluating P loss models is the relative scarcity of available measured field data that adequately capture P losses before and after implementing management practices in a variety of physiographic settings. Here, we describe the development of the P Loss in runoff Events from Agricultural fields Database (PLEAD)—a compilation of event‐based, field‐scale dissolved and/or total P loss runoff loadings from agricultural fields collected at various research sites located in the US Heartland and southern United States. The database also includes runoff and erosion rates; soil‐test P; tillage practices; planting and harvesting rates and practices; fertilizer application rate, method, and timing; manure application rate, method, and timing; and livestock grazing density and timing. In total, >1800 individual runoff events—ranging in duration from 0.4 to 97 h—have been included in the database. Event runoff P losses ranged from <0.05 to 1.3 and 3.0 kg P ha−1 for dissolved and total P, respectively. The data contained in this database have been used in multiple research studies to address important modeling questions relevant to P management planning. We provide these data to encourage additional studies by other researchers. The PLEAD database is available at https://doi.org/10.15482/USDA.ADC/1482380.Core Ideas
Development of database containing P loss from agricultural fields is described.
We provide public access to P loss data for individual runoff events.
The data can be used to evaluate P loss models and P Indices.
}, number={2}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Bolster, Carl H. and Baffaut, Claire and Nelson, Nathan O. and Osmond, Deanna L. and Cabrera, Miguel L. and Ramirez-Avila, John J. and Sharpley, Andrew N. and Veith, Tamie L. and McFarland, Anne M. S. and Senaviratne, Anomaa G. M. M. M. and et al.}, year={2019}, pages={510–517} }
 @article{osmond_shober_sharpley_duncan_hoag_2019, title={Increasing the Effectiveness and Adoption of Agricultural Phosphorus Management Strategies to Minimize Water Quality Impairment}, volume={48}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2019.03.0114}, abstractNote={Phosphorus (P) is essential for optimum agricultural production, but it also causes water quality degradation when lost through erosion (sediment‐attached P), runoff (soluble reactive P; SRP), or leaching (sediment‐attached P or SRP). Implementation of conservation practices (CP) affects P at the source (avoiding), during transport (controlling), or at the water resource edge (trapping). Trade‐offs often occur with CP implementation. For instance, multiple researchers have shown that conservation tillage reduces total P by over 50%, while increasing SRP by upward of 40%. Conservation tillage may increase water quality degradation as SRP is more bioavailable than is particulate P. Conservation practices must be implemented as a system of practices to increase redundancy and to address all loss pathways, such as P management with conservation tillage and a riparian buffer. Further, planning and adoption must be at a watershed scale to ensure practices are placed in critical source areas, thereby providing the most treatment for the least price. Farmers must be involved in watershed planning, which should include financial backstopping and educational outreach. It is imperative that CPs be used more effectively to reduce and retard off‐site P losses. New and innovative CPs are needed to improve control of P leaching, address legacy stores of soil test P, and mitigate increased P losses expected with climate change. Without immediate changes to CP implementation, P losses will increase due to climate change, with a concomitant degradation of water quality. These changes must be made at a watershed scale and in an intentional and transparent manner.Core Ideas
Phosphorus‐reducing conservation practices must control all P pathways.
Phosphorus‐reducing conservation practices must be utilized as systems.
New and innovative conservation practices are needed to improve control of P.
Farmer decision‐making must be considered when implementing conservation practices.
Watershed planning and conservation practice implementation must be intentional.
}, number={5}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Osmond, D. L. and Shober, A. L. and Sharpley, A. N. and Duncan, E. W. and Hoag, D. L. K.}, year={2019}, pages={1204–1217} }
 @article{line_osmond_childres_2019, title={NUTRIENT EXPORT FROM AGRICULTURAL WATERSHEDS IN THE PIEDMONT AND COASTAL PLAIN, NORTH CAROLINA}, volume={62}, ISSN={["2151-0040"]}, DOI={10.13031/trans.13052}, abstractNote={Abstract. Nitrogen (N) and phosphorus (P) input and export rates were determined in six rural, predominantly agricultural watersheds located in the Piedmont and Coastal Plain regions of North Carolina. Water quality monitoring was conducted at the outlets for 2.3 to 8.0 years to determine the annual N and P export from each watershed. Total N and P input and export from five of the six watersheds were correlated, with only a no-till cropland watershed differing. The correlation showed that N and P exports increased by about 4.0% and 8.7%, respectively, of applied N and P for the range of applications rates, whereas dissolved N (NOx-N) export increased by 2.8% with increasing N application rates. Therefore, practices that reduce inputs, such as nutrient management, should result in similar percentage reductions in exports. The Small Watershed Nutrient Forecasting Tool (SWIFT) was used to forecast discharge, N, P, and sediment export from each of the six watersheds. For the no-till cropland watershed, the SWIFT-forecasted N and P export rates were more than 2.5 times those measured, while the sediment export rate was 72 times the measured value. Thus, these data showed that the SWIFT forecasts for N, P, and sediment export were poor for the no-till cropland watershed. For the pasture watershed, the SWIFT forecasts for N and sediment export agreed reasonably well with measured export; however, the forecasted P export was much less than measured. For the four mixed land use watersheds, the SWIFT forecasts for discharge, TN, and sediment were mostly greater than measured, and the forecasted TP export was less than measured for three of the four watersheds. Thus, as with many predicstion tools, SWIFT results must be used with caution.  Keywords: Nutrient export, Nutrient management practice, Water quality monitoring.}, number={5}, journal={TRANSACTIONS OF THE ASABE}, author={Line, D. E. and Osmond, D. L. and Childres, W.}, year={2019}, pages={1135–1145} }
 @article{austin_osmond_shelton_2019, title={Optimum Nitrogen Rates for Maize and Wheat in North Carolina}, volume={111}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2019.04.0286}, abstractNote={Nitrogen decision making and the selection of the “right” N rate in wheat (Triticum aestivum L.) and maize (Zea mays L.) are difficult due to complex interactions in the N cycle with weather, management, and genetics. An adaptive management approach utilizing farmer networks and participatory learning was established to refine N rate decisions. On‐farm trials were established to reflect grower N rate with additional treatments of ±25% N. In 79 site‐years of wheat, N−25%, Nstd, and N+25% rate treatments were best in 37, 35, and 28% of the trials, respectively. In 100 site‐years of maize, N−25%, Nstd, and N+25% rate treatments were best in 58, 30, and 12% of the trials, respectively. Grower’s selected N rates in wheat were similar to recommendations from the North Carolina Realistic Yield Expectation (RYE) database while maize N rates were an average 48 kg ha−1 higher; however, N−25% rates, which were best 58% of the time, were similar to RYE N rate. Doppler‐based estimates of total precipitation from the National Weather Center explained 90% of the average maize yield variability. However, site‐yield was independent of location, N rate, and total precipitation. Measures of performance (N factor productivity and N balance) varied with achieved yields but indicate most growers apply N adequate to maintain organic N lost through mineralization. Results suggest that improved approaches to N rate selection and N efficiency will likely require in‐season adjustments to yield‐based N rates that incorporate local management and environmental conditions throughout the growing season.Core Ideas

Yield level and response is independent of location, N rate, and total precipitation.
Doppler‐based rainfall estimates help explain seasonal trends in yield.
Growers often select N rates greater than recommended for maize but not wheat.
}, number={5}, journal={AGRONOMY JOURNAL}, author={Austin, Robert and Osmond, Deanna and Shelton, Shelby}, year={2019}, pages={2558–2568} }
 @article{duncan_osmond_shober_starr_tomlinson_kovar_moorman_peterson_fiorellino_reid_2019, title={Phosphorus and Soil Health Management Practices}, volume={4}, ISSN={["2471-9625"]}, DOI={10.2134/ael2019.04.0014}, abstractNote={Core Ideas
Trade‐offs exist in nutrient losses for soil health management.
Combining soil health practices and other BMPs can exacerbate or mitigate P losses.
There are limitations of soil health practices and reducing P losses.
Educators should discuss BMP trade‐offs associated with P loss.
Soil health has gained widespread attention in agronomic and conservation communities due to its many purported benefits, including claims that implementation of core soil health practices (e.g., conservation tillage, cover crops) will improve water quality by curtailing runoff losses of nutrients such as phosphorus (P). However, a review of the existing literature points to well‐established findings regarding trade‐offs in water quality outcomes following the implementation of core soil health practices. In fact, both conservation tillage and cover crops can exacerbate dissolved P losses, undermining other benefits such as reductions in particulate P (sediment‐bound P) losses. Soil health management must be pursued in a manner that considers the complex interaction of nutrient cycling processes and produces realistic expectations. Achieving water quality goals through soil health practices will require adaptive management and continued, applied research to support evidence‐based farm management decisions.}, number={1}, journal={AGRICULTURAL & ENVIRONMENTAL LETTERS}, author={Duncan, Emily W. and Osmond, Deanna L. and Shober, Amy L. and Starr, Laura and Tomlinson, Peter and Kovar, John L. and Moorman, Thomas B. and Peterson, Heidi M. and Fiorellino, Nicole M. and Reid, Keith}, year={2019}, month={Jul} }
 @article{duriancik_flahive_osmond_2018, title={Application of monitoring to inform policy and programs and achieve water quality goals}, volume={73}, ISSN={["1941-3300"]}, DOI={10.2489/jswc.73.1.11a}, abstractNote={Water quality monitoring is used throughout the world to assess the quality of water resources. Data and analyses from assessments can be used to inform policy as well as program design, delivery approaches, practice design, and adaptive management to enhance outcomes. Many of these assessments have demonstrated problems associated with nutrient enrichment and sedimentation of water resources (Chapman 1996; Dubrovsky and Hamilton 2010; Scott and Gemmell 2013). Not surprisingly, because of its land area and necessary inputs to support food production services, agriculture can be a major source of nutrients and sediment (USEPA 2008), contributing to the impairment of water resources across the globe. Key water quality monitoring programs to document large-scale water quality status or trends exist. These are useful for tracking changes in water resource condition and trends over time in basins or large water bodies, but are often not fine enough resolution alone to attribute effects to specific actions or understand the processes occurring or being influenced by management. Water quality monitoring can also be used to document the effectiveness of agricultural conservation practices at both the field and watershed scale. There is a significant body of edge-of-field and plot research documenting reductions from diverse practices ranging…}, number={1}, journal={JOURNAL OF SOIL AND WATER CONSERVATION}, author={Duriancik, Lisa F. and Flahive, Katie and Osmond, Deanna}, year={2018}, pages={11A–15A} }
 @article{osmond_austin_shelton_es_sela_2018, title={Evaluation of Adapt-N and Realistic Yield Expectation Approaches for Maize Nitrogen Management in North Carolina}, volume={82}, ISSN={["1435-0661"]}, DOI={10.2136/sssaj2018.03.0127}, abstractNote={
Core Ideas
The North Carolina nitrogen database made better recommendations than Adapt‐N for plot studies.
Different labs produce distinctly different soil organic matter percentages from the same soil.
Farmer strip trial results demonstrated approximately 60% of the time that Grower‐25% N yielded similarly to the other treatments.
Farmer strip trial results showed overall similar performance for Adapt‐N and Grower‐Consultant rates.
Nitrogen decision making for maize (Zea mays L.) is difficult because of seasonal weather fluctuations. New tools have emerged based on dynamic simulation models that account for weather variability. We evaluated the performance of the Adapt‐N tool relative to North Carolina's Realistic Yield Expectation (RYE) framework through six multi‐N rate maize plot trials in three physiographic regions and 38 strip trials on commercial farms in the coastal plain. Yield response and profit were evaluated with quadratic plateau (QP) response curves. The RYE framework generally estimated the agronomic optimum N rate (AONR) well, as did Adapt‐N after modification to account for high soil organic matter (SOM) and C/N ratio mineral‐organic coastal plain soil; there was, however, much greater site variability with Adapt‐N. Adapt‐N was sensitive to SOM content inputs, which varied based on method and laboratory. The RYE provided overall higher dollar return than Adapt‐N; Adapt‐N returns varied based on SOM and yield goal inputs, since they strongly impact N rate recommendations. In the on‐farm strip‐trials, 58% of yields were not statistically different between lower N rates and other treatments including Adapt‐N. On average, Adapt‐N performed similar to grower‐consultant practice with modest tradeoffs between reduced N rates and yield. Adapt‐N recommendations and grower rates yielded higher than RYE and required more N. Overall, the RYE approach performed better than Adapt‐N in N research farm trials; in on‐farm strip trials Adapt‐N performed similarly to grower‐consultant practices and in various cases provided economical yield increases over RYE.}, number={6}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Osmond, Deanna and Austin, Robert and Shelton, Shelby and Es, Harold and Sela, Shai}, year={2018}, pages={1449–1458} }
 @article{franzluebbers_pershing_crozier_osmond_schroeder-moreno_2018, title={Soil-Test Biological Activity with the Flush of CO2: I.C and N Characteristics of Soils in Corn Production}, volume={82}, ISSN={["1435-0661"]}, DOI={10.2136/sssaj2017.12.0433}, abstractNote={
Core Ideas
Soil nitrogen mineralization can be predicted with the flush of CO2.
Soil texture does not alter the relationship between the flush of CO2 and N mineralization.
Large quantity of mineralizable N in surface soils is possible with conservation management.
The flush of CO2 is an appropriate indicator for soil‐test biological activity.
The flush of CO2 is a rapid and reliable indicator of soil N availability.
Nitrogen limits crop production when insufficient and harms the environment when excessive. Tailoring N inputs to cropping systems remains a high priority to achieve production and environmental goals. We collected soils from 47 corn (Zea mays L.) production fields in North Carolina and Virginia at depths of 0 to 10, 10 to 20, and 20 to 30 cm and evaluated soil C and N characteristics in association with soil N mineralization. Soil organic C at a depth of 0 to 10 cm varied among sites from ∼10 to 80 g kg–1, and generally declined with depth because of many sites with no‐tillage management. Net N mineralization during 24 d of aerobic incubation (25°C, 50% water‐filled pore space) was 54 to 114 mg N kg–1 (24 d)–1 at 0 to 10 cm, 22 to 41 mg N kg–1 (24 d)–1 at 10 to 20 cm, and 12 to 22 mg N kg–1 (24 d)–1 at 20 to 30 cm (middle 50% of observations at each depth). Total soil N was positively associated with net N mineralization (r2 = 0.58), but the flush of CO2 during 3 d was even more closely associated with net N mineralization (r2 = 0.77). Association between the flush of CO2 and net N mineralization did not change significantly when data were sorted by different regions or soil textural classes. The flush of CO2 is a rapid, reliable, and robust indicator of soil‐test biological activity. The strong association of the flush of CO2 with net N mineralization also corroborated use of the flush of CO2 as a rapid and reliable indicator of soil N availability.}, number={3}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Franzluebbers, Alan J. and Pershing, Mary R. and Crozier, Carl and Osmond, Deanna and Schroeder-Moreno, Michelle}, year={2018}, pages={685–695} }
 @misc{morris_murrell_beegle_camberato_ferguson_grove_ketterings_kyveryga_laboski_mcgrath_et al._2018, title={Strengths and Limitations of Nitrogen Rate Recommendations for Corn and Opportunities for Improvement}, volume={110}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2017.02.0112}, abstractNote={Core Ideas
Nitrogen recommendations for individual corn fields are less accurate than desired.Nitrogen recommendations need improvement for economic and environmental reasons.A review of fundamental concepts will improve understanding about N recommendations.Examination of N recommendation systems, tests, and models will improve recommendations.
Nitrogen fixation by the Haber–Bosch process has more than doubled the amount of fixed N on Earth, significantly influencing the global N cycle. Much of this fixed N is made into N fertilizer that is used to produce nearly half of the world's food. Too much of the N fertilizer pollutes air and water when it is lost from agroecosystems through volatilization, denitrification, leaching, and runoff. Most of the N fertilizer used in the United States is applied to corn (Zea mays L.), and the profitability and environmental footprint of corn production is directly tied to N fertilizer applications. Accurately predicting the amount of N needed by corn, however, has proven to be challenging because of the effects of rainfall, temperature, and interactions with soil properties on the N cycle. For this reason, improving N recommendations is critical for profitable corn production and for reducing N losses to the environment. The objectives of this paper were to review current methods for estimating N needs of corn by: (i) reviewing fundamental background information about how N recommendations are created; (ii) evaluating the performance, strengths, and limitations of systems and tools used for making N fertilizer recommendations; (iii) discussing how adaptive management principles and methods can improve recommendations; and (iv) providing a framework for improving N fertilizer rate recommendations.}, number={1}, journal={AGRONOMY JOURNAL}, author={Morris, Thomas F. and Murrell, T. Scott and Beegle, Douglas B. and Camberato, James J. and Ferguson, Richard B. and Grove, John and Ketterings, Quirine and Kyveryga, Peter M. and Laboski, Carrie A. M. and McGrath, Joshua M. and et al.}, year={2018}, pages={1–37} }
 @article{motallebi_hoag_tasdighi_arabi_osmond_2017, title={An economic inquisition of water quality trading programs, with a case study of Jordan Lake, NC}, volume={193}, ISSN={["1095-8630"]}, DOI={10.1016/j.jenvman.2017.02.039}, abstractNote={A water quality trading (WQT) program was promulgated in North Carolina to address water quality issues related to nutrients in the highly urbanizing Jordan Lake Watershed. Although WQT programs are appealing in theory, the concept has not proved feasible in several attempts between point and nonpoint polluters in the United States. Many application hurdles that create wedges between success and failure have been evaluated in the literature. Most programs, however, face multiple hurdles; eliminating one may not clear a pathway to success. Therefore, we identify and evaluate the combined impact of four different wedges including baseline, transaction cost, trading ratio, and trading cost in the Jordan Lake Watershed program. Unfortunately, when applied to the Jordan Lake program, the analysis clearly shows that a traditional WQT program will not be feasible or address nutrient management needs in a meaningful way. The hurdles individually would be difficult to overcome, but together they appear to be unsurmountable. This analysis shows that there is enough information to pre-identify potential hurdles that could inform policy makers where, and how, the concept might work. It would have saved time, energy, and financial resources if North Carolina had done so before embarking to implement their program in the Jordan Lake Watershed.}, journal={JOURNAL OF ENVIRONMENTAL MANAGEMENT}, author={Motallebi, Marzieh and Hoag, Dana L. and Tasdighi, Ali and Arabi, Mazdak and Osmond, Deanna L.}, year={2017}, month={May}, pages={483–490} }
 @article{robarge_duckworth_osmond_smyth_river_2017, title={Commentary on "A possible trade-off between clean air and clean water" by Smith et al. (2017)}, volume={72}, ISSN={["1941-3300"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85033378332&partnerID=MN8TOARS}, DOI={10.2489/jswc.72.6.121a}, abstractNote={Authors of the recent feature article by Smith et al., which was published in the A Section of the July/August 2017 issue of the Journal of Soil and Water Conservation (A Section articles are not peer-reviewed while articles in the Research Section of the journal are peer-reviewed), have conducted water quality research in the Western Lake Erie Basin (WLEB) and demonstrated multiple potential causes of increased soluble phosphorous (SP) loading, including agricultural practice changes such as increased no-till, tile drainage, surface application of fall fertilizer, and weather. In their article, “A possible trade-off between clean air and clean water,” these authors propose an additional cause: the connection between the success of the Clean Air Act in improving air quality in the United States and increases in SP loading that have contributed to harmful algal blooms in the WLEB. Although we agree that scientists must always be vigilant for pernicious consequences of well-meaning actions, we believe that there are flaws in the study design and data interpretation that undermine the conclusion of article. Specifically, what we see as flaws in the interpretation of the data presented in table 1 and figures 2 and 3 are described below. Furthermore, the authors do…}, number={6}, journal={JOURNAL OF SOIL AND WATER CONSERVATION}, author={Robarge, Wayne and Duckworth, Owen and Osmond, Deanna and Smyth, Jot and River, Mark}, year={2017}, pages={121A–122A} }
 @article{bolster_forsberg_mittelstet_radcliffe_storm_ramirez-avila_sharpley_osmond_2017, title={Comparing an Annual and a Daily Time-Step Model for Predicting Field-Scale Phosphorus Loss}, volume={46}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2016.04.0159}, abstractNote={A wide range of mathematical models are available for predicting phosphorus (P) losses from agricultural fields, ranging from simple, empirically based annual time‐step models to more complex, process‐based daily time‐step models. In this study, we compare field‐scale P‐loss predictions between the Annual P Loss Estimator (APLE), an empirically based annual time‐step model, and the Texas Best Management Practice Evaluation Tool (TBET), a process‐based daily time‐step model based on the Soil and Water Assessment Tool. We first compared predictions of field‐scale P loss from both models using field and land management data collected from 11 research sites throughout the southern United States. We then compared predictions of P loss from both models with measured P‐loss data from these sites. We observed a strong and statistically significant (p < 0.001) correlation in both dissolved (ρ = 0.92) and particulate (ρ = 0.87) P loss between the two models; however, APLE predicted, on average, 44% greater dissolved P loss, whereas TBET predicted, on average, 105% greater particulate P loss for the conditions simulated in our study. When we compared model predictions with measured P‐loss data, neither model consistently outperformed the other, indicating that more complex models do not necessarily produce better predictions of field‐scale P loss. Our results also highlight limitations with both models and the need for continued efforts to improve their accuracy.Core Ideas
We compared predictions of P loss between an empirically‐based and process‐based model.
Predictions from both models were well correlated with each other.
The process‐based model did not result in noticeably better predictions of P loss.
APLE predicted greater DP loss and TBET predicted greater PP loss.
Results indicate the need for improving accuracy of both models.
}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Bolster, Carl H. and Forsberg, Adam and Mittelstet, Aaron and Radcliffe, David E. and Storm, Daniel and Ramirez-Avila, John and Sharpley, Andrew N. and Osmond, Deanna}, year={2017}, pages={1314–1322} }
 @article{rajkovich_osmond_weisz_crozier_israel_austin_2017, title={Evaluation of Nitrogen-Loss Prevention Amendments in Maize and Wheat in North Carolina}, volume={109}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2016.03.0153}, abstractNote={Core Ideas
Fertilizer additives to decrease N losses did not provide consistent yield advantages.
Plots treated with N‐loss products did not increase N use efficiency or N uptake.
Agronomic optimum N rates observed in the field aligned with North Carolina recommendations.
To reduce environmental losses of N and increase crop use, it is critical to optimize N fertilization rates and determine if N‐loss prevention amendments increase yields. Research objectives were to: (i) determine N‐release patterns of three N‐loss amendments (urea ammonium nitrate [UAN] treated with NBPT+DCD, nitrapyrin, or an organo‐Ca) and UAN through a laboratory incubation; (ii) determine effectiveness of these four products for maize (Zea mays L.) and winter wheat (Triticum aestivum L.) produced in two to three regions of North Carolina; and (iii) determine agronomic optimum N rate for wheat and corn compared to state‐recommended rates. Nitrogen release was measured in three soils (coastal plain, piedmont, and mountains) during the incubation experiment. Field experiments were randomized complete block designs (four replications of six maize N rates and five wheat N rates), with each rate applied as one of four product treatments (UAN and UAN+ one of three N‐loss prevention amendments). In the incubation experiment, soils treated with UAN+nitrapyrin or UAN+NBPT+DCD delayed nitrification longer than soils treated with UAN or UAN+organo‐Ca. There was no significant effect of product on maize grain yield (coastal plain and mountains) and wheat yield (coastal plain and piedmont). A year × product interaction occurred for maize grain yield in the piedmont. Agronomic optimum N rates mostly aligned with current North Carolina N fertilizer recommendations. Despite positive laboratory results, N‐loss amendments did not have a significant effect on yield in 9 of 10 site‐years, indicating that proper N rates are a more effective nutrient management strategy.}, number={5}, journal={AGRONOMY JOURNAL}, author={Rajkovich, Shelby and Osmond, Deanna and Weisz, Randy and Crozier, Carl and Israel, Daniel and Austin, Robert}, year={2017}, pages={1811–1824} }
 @article{sharpley_kleinman_baffaut_beegle_bolster_collick_easton_lory_nelson_osmond_et al._2017, title={Evaluation of Phosphorus Site Assessment Tools: Lessons from the USA}, volume={46}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2016.11.0427}, abstractNote={Critical source area identification through phosphorus (P) site assessment is a fundamental part of modern nutrient management planning in the United States, yet there has been only sparse testing of the many versions of the P Index that now exist. Each P site assessment tool was developed to be applicable across a range of field conditions found in a given geographic area, making evaluation extremely difficult. In general, evaluation with in‐field monitoring data has been limited, focusing primarily on corroborating manure and fertilizer “source” factors. Thus, a multiregional effort (Chesapeake Bay, Heartland, and Southern States) was undertaken to evaluate P Indices using a combination of limited field data, as well as output from simulation models (i.e., Agricultural Policy Environmental eXtender, Annual P Loss Estimator, Soil and Water Assessment Tool [SWAT], and Texas Best Management Practice Evaluation Tool [TBET]) to compare against P Index ratings. These comparisons show promise for advancing the weighting and formulation of qualitative P Index components but require careful vetting of the simulation models. Differences among regional conclusions highlight model strengths and weaknesses. For example, the Southern States region found that, although models could simulate the effects of nutrient management on P runoff, they often more accurately predicted hydrology than total P loads. Furthermore, SWAT and TBET overpredicted particulate P and underpredicted dissolved P, resulting in correct total P predictions but for the wrong reasons. Experience in the United States supports expanded regional approaches to P site assessment, assuming closely coordinated efforts that engage science, policy, and implementation communities, but limited scientific validity exists for uniform national P site assessment tools at the present time.Core Ideas
Concern over the accuracy of P Indices has led to calls for their evaluation.
Insufficient field data exist to evaluate P site assessment tools comprehensively.
Researchers can use nonpoint source models as surrogates to field data if vetted first.
There is no scientific justification for a single national P Index.
}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Sharpley, Andrew and Kleinman, Peter and Baffaut, Claire and Beegle, Doug and Bolster, Carl and Collick, Amy and Easton, Zachary and Lory, John and Nelson, Nathan and Osmond, Deanna and et al.}, year={2017}, pages={1250–1256} }
 @article{merriman_moore_wang_osmond_al-rubaei_smolek_blecken_viklander_hunt_2017, title={Evaluation of factors affecting soil carbon sequestration services of stormwater wet retention ponds in varying climate zones}, volume={583}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2017.01.040}, abstractNote={The carbon sequestration services of stormwater wet retention ponds were investigated in four different climates: U.S., Northern Sweden, Southern Sweden, and Singapore, representing a range of annual mean temperatures, growing season lengths and rainfall depths: geographic factors that were not statistically compared, but have great effect on carbon (C) accumulation. A chronosequence was used to estimate C accumulations rates; C accumulation and decomposition rates were not directly measured. C accumulated significantly over time in vegetated shallow water areas (0-30cm) in the USA (78.4gCm -2 yr -1 ), in vegetated temporary inundation zones in Sweden (75.8gCm -2 yr -1 ), and in all ponds in Singapore (135gCm -2 yr -1 ). Vegetative production appeared to exert a stronger influence on relative C accumulation rates than decomposition. Comparing among the four climatic zones, the effects of increasing rainfall and growing season lengths (vegetative production) outweighed the effects of higher temperature on decomposition rates. Littoral vegetation was a significant source to the soil C pool relative to C sources draining from watersheds. Establishment of vegetation in the shallow water zones of retention ponds is vital to providing a C source to the soil. Thus, the width of littoral shelves containing this vegetation along the perimeter may be increased if C sequestration is a design goal. This assessment establishes that stormwater wet retention ponds can sequester C across different climate zones with generally annual rainfall and lengths of growing season being important general factors for C accumulation.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Merriman, L. S. and Moore, T. L. C. and Wang, J. W. and Osmond, D. L. and Al-Rubaei, A. M. and Smolek, A. P. and Blecken, G. T. and Viklander, M. and Hunt, W. F.}, year={2017}, month={Apr}, pages={133–141} }
 @article{ramirez-avila_radcliffe_osmond_bolster_sharpley_ortega-achury_forsberg_oldham_2017, title={Evaluation of the APEX Model to Simulate Runoff Quality from Agricultural Fields in the Southern Region of the United States}, volume={46}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2017.07.0258}, abstractNote={The Agricultural Policy Environmental eXtender (APEX) model has been widely applied to assess phosphorus (P) loss in runoff water and has been proposed as a model to support practical decisions regarding agricultural P management, as well as a model to evaluate tools such as the P Index. The aim of this study is to evaluate the performance of APEX to simulate P losses from agricultural systems to determine its potential use for refinement or replacement of the P Index in the southern region of the United States. Uncalibrated and calibrated APEX model predictions were compared against measured water quality data from row crop fields in North Carolina and Mississippi and pasture fields in Arkansas and Georgia. Calibrated models satisfactorily predicted event‐based surface runoff volumes at all sites (Nash‐Sutcliffe efficiency [NSE] > 0.47, |percent bias [PBIAS]| < 34) except Arkansas (NSE < 0.11, |PBIAS| < 50) but did not satisfactory simulate sediment, dissolved P, or total P losses in runoff water. The APEX model tended to underestimate dissolved and total P losses from fields where manure was surface applied. The model also overestimated sediments and total P loads during irrigation events. We conclude that the capability of APEX to predict sediment and P losses is limited, and consequently so is the potential for using APEX to make P management recommendations to improve P Indices in the southern United States.Core Ideas
Calibrated APEX reasonably predicted runoff in no‐tillage and conventional tillage fields.
APEX was unsatisfactory in predicting sediment losses, especially from pasture fields.
P loss was inadequately predicted, especially in fields with surface applied manure.
Adding a surface manure P pool to APEX could improve P model predictions.
Improving P model predictions allow it to be used to refine southern region P Indices.
}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Ramirez-Avila, John J. and Radcliffe, David E. and Osmond, Deanna and Bolster, Carl and Sharpley, Andrew and Ortega-Achury, Sandra L. and Forsberg, Adam and Oldham, J. Larry}, year={2017}, pages={1357–1364} }
 @article{forsberg_radcliffe_bolster_mittelstet_storm_osmond_2017, title={Evaluation of the TBET Model for Potential Improvement of Southern P Indices}, volume={46}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2016.06.0210}, abstractNote={Due to a shortage of available phosphorus (P)‐loss datasets, simulated data from an accurate quantitative P transport model could be used to evaluate a P Index. The objective of this study was to compare predictions from the Texas Best Management Practice Evaluation Tool (TBET) against measured P‐loss data to determine whether the model could be used to improve P Indices in the southern region. Measured P‐loss data from field‐scale study sites in Arkansas, Georgia, and North Carolina were used to assess the accuracy of TBET for predicting field‐scale loss of P. We found that event‐based predictions using an uncalibrated model were generally poor. Calibration improved runoff predictions and produced scatterplot regression lines that had slopes near one and intercepts near zero. However, TBET predictions of runoff met the performance criteria (Nash–Sutcliffe efficiency ≥ 0.3, percent bias ≤ 35%, and mean absolute error ≤ 10 mm) in only one out of six comparisons: North Carolina during calibration. Sediment predictions were imprecise, and dissolved P predictions underestimated measured losses. In North Carolina, total P‐loss predictions were reasonably accurate because TBET did a slightly better job of predicting sediment losses from cultivated land. In Arkansas and Georgia, where the experimental sites were in forage production, the underprediction of dissolved P led directly to the underpredictions of total P. We conclude that TBET cannot be used to improve southern P Indices, but a curve number approach could be incorporated into P Indices to improve runoff predictions.Core Ideas
Predictions from an accurate P transport model could be used to evaluate a P Index.
Predictions from an uncalibrated TBET model were generally poor.
A calibrated TBET model was better but did not meet the performance criteria.
A curve number approach for runoff could be incorporated into P Indices.
}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Forsberg, Adam and Radcliffe, David E. and Bolster, Carl H. and Mittelstet, Aaron and Storm, Daniel E. and Osmond, Deanna}, year={2017}, pages={1341–1348} }
 @misc{hoag_arabi_osmond_ribaudo_motallebi_tasdighi_2017, title={POLICY UTOPIAS FOR NUTRIENT CREDIT TRADING PROGRAMS WITH NONPOINT SOURCES}, volume={53}, ISSN={["1752-1688"]}, DOI={10.1111/1752-1688.12532}, abstractNote={AbstractA promising program to address water contamination from nutrients is water quality trading (WQT), whereby entities with high abatement costs purchase credits from entities with lower abatement costs. The concept has found some success with point source water pollution, but very few trades have occurred in over 50 programs in the United States (U.S.) that have focused on nonpoint sources (NPSs). To understand why success has been slow, we identified three environments needed for programs to succeed: physical, economic, and institutional. We estimate that only 5% of watersheds in the U.S. currently listed as nutrient impaired provide a viable physical environment for trading nitrogen; 13% are suitable for phosphorus. Economic and institutional challenges would shrink that domain even further. Therefore, we find places with the ideal physical, economic, and institutional environments necessary for feasible WQT programs are virtual policy utopias — rare places with ideal environments. Fortunately, a growing literature provides the tools necessary to identify where these policy utopias are and to expand that domain through a better understanding about how to manage WQT programs more effectively.}, number={3}, journal={JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION}, author={Hoag, Dana L. K. and Arabi, Mazdak and Osmond, Deanna and Ribaudo, Marc and Motallebi, Marzieh and Tasdighi, Ali}, year={2017}, month={Jun}, pages={514–520} }
 @article{roper_osmond_heitman_wagger_reberg-horton_2017, title={Soil Health Indicators Do Not Differentiate among Agronomic Management Systems in North Carolina Soils}, volume={81}, ISSN={["1435-0661"]}, DOI={10.2136/sssaj2016.12.0400}, abstractNote={Recent soil tests evaluating “soil health” on a broad scale may not properly consider the intrinsic limitations of soil properties, and have not been assessed in regionally unique soil conditions. To evaluate three soil tests in North Carolina, we used long-term agronomic management trials from three distinct physiographic regions: mountain (22 yr), piedmont (32 yr), and coastal plain (17 yr). Mountain and coastal plain trials included combinations of organic or chemical management with or without tillage; the piedmont trial included nine different tillage treatments. Soil samples were collected and submitted for analysis as recommended by the North Carolina Department of Agriculture and Consumer Services, Haney soil health test (HSHT), and Cornell comprehensive assessment of soil health (CASH). Plant nutrient concentrations varied but were still sufficient for crops. The CASH physical soil indicators, such as surface hardness and aggregate stability, were not statistically different, regardless of tillage intensity or management. Biological soil indicators (e.g., CO₂ respiration) responded differently to management, but this differentiation was inconsistent among locations and tests. Despite many years of conservation management, the CASH results described mountain soils as “low” or “very low” soil health for all but no-till organic management, which received a “medium” score. The HSHT results considered soil from all but moldboard plowing (piedmont) to be in good health. Finally, there was no correlation between soil health tests and crop yields from North Carolina soils. Soil health tests should be calibrated to better differentiate among soil management effects that vary depending on intrinsic soil limitations.}, number={4}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Roper, Wayne R. and Osmond, Deanna L. and Heitman, Joshua L. and Wagger, Michael G. and Reberg-Horton, S. Chris}, year={2017}, pages={828–843} }
 @article{osmond_bolster_sharpley_cabrera_feagley_forsberg_mitchell_mylavarapu_oldham_radcliffe_et al._2017, title={Southern Phosphorus Indices, Water Quality Data, and Modeling (APEX, APLE, and TBET) Results: A Comparison}, volume={46}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2016.05.0200}, abstractNote={Phosphorus (P) Indices in the southern United States frequently produce different recommendations for similar conditions. We compared risk ratings from 12 southern states (Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, and Texas) using data collected from benchmark sites in the South (Arkansas, Georgia, Mississippi, North Carolina, Oklahoma, and Texas). Phosphorus Index ratings were developed using both measured erosion losses from each benchmark site and Revised Universal Soil Loss Equation 2 predictions; mostly, there was no difference in P Index outcome. The derived loss ratings were then compared with measured P loads at the benchmark sites by using equivalent USDA–NRCS P Index ratings and three water quality models (Annual P Loss Estimator [APLE], Agricultural Policy Environmental eXtender [APEX], and Texas Best Management Practice Evaluation Tool [TBET]). Phosphorus indices were finally compared against each other using USDA–NRCS loss ratings model estimate correspondence with USDA–NRCS loss ratings. Correspondence was 61% for APEX, 48% for APLE, and 52% for TBET, with overall P index correspondence at 55%. Additive P Indices (Alabama and Texas) had the lowest USDA–NRCS loss rating correspondence (31%), while the multiplicative (Arkansas, Florida, Louisiana, Mississippi, South Carolina, and Tennessee) and component (Georgia, Kentucky, and North Carolina) indices had similar USDA–NRCS loss rating correspondence—60 and 64%, respectively. Analysis using Kendall's modified Tau suggested that correlations between measured and calculated P‐loss ratings were similar or better for most P Indices than the models.Core Ideas
Southern region P Indices estimate P losses as well as water quality models.
APLE and TBET P‐loss predictions were more similar than were results from APEX.
Assigning potential P‐loss risk from P Indices to any given water resource is challenging.
}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Osmond, Deanna and Bolster, Carl and Sharpley, Andrew and Cabrera, Miguel and Feagley, Sam and Forsberg, Adam and Mitchell, Charles and Mylavarapu, Rao and Oldham, J. Larry and Radcliffe, David E. and et al.}, year={2017}, pages={1296–1305} }
 @article{kleinman_sharpley_buda_easton_lory_osmond_radcliffe_nelson_veith_doody_2017, title={The Promise, Practice, and State of Planning Tools to Assess Site Vulnerability to Runoff Phosphorus Loss}, volume={46}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2017.10.0395}, abstractNote={Over the past 20 yr, there has been a proliferation of phosphorus (P) site assessment tools for nutrient management planning, particularly in the United States. The 19 papers that make up this special section on P site assessment include decision support tools ranging from the P Index to fate‐and‐transport models to weather‐forecast‐based risk calculators. All require objective evaluation to ensure that they are effective in achieving intended benefits to protecting water quality. In the United States, efforts have been underway to compare, evaluate, and advance an array of P site assessment tools. Efforts to corroborate their performance using water quality monitoring data confirms previously documented discrepancies between different P site assessment tools but also highlights a surprisingly strong performance of many versions of the P Index as a predictor of water quality. At the same time, fate‐and‐transport models, often considered to be superior in their prediction of hydrology and water quality due to their complexity, reveal limitations when applied to site assessment. Indeed, one consistent theme from recent experience is the need to calibrate highly parameterized models. As P site assessment evolves, so too do routines representing important aspects of P cycling and transport. New classes of P site assessment tools are an opportunity to move P site assessment from general, strategic goals to web‐based tools supporting daily, operational decisions.Core Ideas
Corroboration of decision support tools for controlling phosphorus loss is limited.
Phosphorus Index is often better related to water quality than fate‐and‐transport models.
New site assessment tools for phosphorus must undergo rigorous verification.
Informed calibration of fate and transport models often improves model performance.
Care must be taken not to overparameterize fate‐and‐transport models.
}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Kleinman, P. J. A. and Sharpley, A. N. and Buda, A. R. and Easton, Z. M. and Lory, J. A. and Osmond, D. L. and Radcliffe, D. E. and Nelson, N. O. and Veith, T. L. and Doody, D. G.}, year={2017}, pages={1243–1249} }
 @article{motallebi_hoag_tasdighi_arabi_osmond_boone_2018, title={The impact of relative individual ecosystem demand on stacking ecosystem credit markets}, volume={29}, ISSN={["2212-0416"]}, DOI={10.1016/j.ecoser.2017.12.010}, abstractNote={A blended actual and hypothetical vertical ecosystem services stacking scenario is developed for a water quality trading (WQT) program in North Carolina. Demand is estimated for total nitrogen reduction and simulated for total phosphorous reduction. Nitrogen and phosphorus are complementary pollutants jointly produced by a single conservation practice, riparian buffers. The supply of reduction is based on the amount of riparian buffers that would be implemented by farmers at a given offering price for WQT credits. Nitrogen reduction is the primary ecosystem service that already has a market in the form of a WQT program. Phosphorus reduction is a hypothetical, secondary ecosystem service that we introduce to evaluate ecosystem stacking. We specifically evaluate stacking in thin markets, where there are few buyers and/or sellers. Our detailed analysis shows that the relative size of demand for different services plays a profound role in the success of stacking when markets are thin; and many if not most ecosystem markets are thin. A secondary service with relatively low demand will either be too small (insufficient) to generate any new credits, or, in a non-competitive market with few sellers, produce no additionality of the secondary service (double dipping). In these two cases, sponsors of the secondary market should not make payments since they will receive no additional benefits above what would have been achieved under conservation practices implemented for the primary ecosystem service. We find that ecosystem stacking is most likely to generate more revenue to producers and to reduce pollution emissions when demand for the secondary service is comparable in magnitude to the primary service. Accurate assessment of relative demand can help policy makers determine where stacking might work, and help purchasers avoid paying for services without results, especially where markets are thin.}, journal={ECOSYSTEM SERVICES}, author={Motallebi, Marzieh and Hoag, Dana L. and Tasdighi, Ali and Arabi, Mazdak and Osmond, Deanna L. and Boone, Randall B.}, year={2018}, month={Feb}, pages={137–144} }
 @article{o'connell_motallebi_osmond_hoag_2017, title={Trading on risk: The moral logics and economic reasoning of North Carolina farmers in water quality trading markets}, volume={4}, ISSN={["2330-4847"]}, DOI={10.1002/sea2.12090}, abstractNote={Water quality trading (WQT) is a popular policy for improving the quality of waterways across the United States by reducing water pollution. However, in established markets, few trades are happening, making environmental gains from WQT limited. Despite these trends, policy makers continue to implement this market-based approach to achieve clean water. Successful markets rely on stakeholders' willingness to buy and sell in the market, yet research has not focused on this aspect of WQT. The stakeholders involved in WQT are frequently farmers (as sellers) trading with developers and urban municipalities (as buyers). To better understand stakeholder decisions about WQT, this research sought to document barriers and catalysts for farmers participation in a brand-new WQT program in the Jordan Lake Watershed, North Carolina. Key findings from interviews with ninety farmers show that most have high conservation rates and know about local water problems. Nevertheless, they were unwilling or unlikely to participate in the program. We offer detailed evidence of the complex ways farmers calculate risk for farm practices and environmental health as an indication that their perceptions of risk and moral sensibilities involve a broader set of costs and values than accounted for in the WQT policy design, ultimately making trading unviable.}, number={2}, journal={ECONOMIC ANTHROPOLOGY}, author={O'Connell, Caela and Motallebi, Marzieh and Osmond, Deanna L. and Hoag, Dana L. K.}, year={2017}, month={Jun}, pages={225–238} }
 @article{jameson_white_osmond_aziz_2016, title={Determination of Biosolids Phosphorus Solubility and Its Relationship to Wastewater Treatment}, volume={88}, ISSN={["1554-7531"]}, DOI={10.2175/106143016x14609975746406}, abstractNote={ABSTRACT:In North Carolina (NC), biosolids land application rates governed by crop nitrogen (N) requirements typically surpass crop phosphorus (P) needs, increasing surface water pollution potential. The NC Department of Environmental Quality (NCDEQ) is considering P‐based biosolids application guidelines for some nutrient‐impaired watersheds using the P Loss Assessment Tool (PLAT), but important biosolids information is lacking: total P (TP), water‐extractable P (WEP), and percent water‐extractable P (PWEP). In each of three seasons, we sampled 28 biosolids from 26 participating water resource recovery facilities (WRRFs) and analyzed for TP, WEP, and percent dry matter (DM), from which PWEP and nonsoluble P were calculated. Based on descriptive statistics and an online survey of treatment processes, biosolids were divided into Class A‐alkaline, Class A‐heat, Class B‐slurry, and Class B‐cake. The average TP in Class A alkaline stabilized biosolids was more than five times less than the average of the other biosolids, 5.0 vs. 26.6 g/kg, respectively. Averaged over biosolids, WEP and PWEP were 1.4 g/kg and 5.0%, respectively. Stabilization processes appeared to reduce WEP substantially, so biosolids potential soluble‐P loss is low. Our data will allow PLAT to be used for biosolids P‐loss risk assessments.}, number={7}, journal={WATER ENVIRONMENT RESEARCH}, publisher={Water Environment Federation}, author={Jameson, Molly and White, Jeffrey G. and Osmond, Deanna L. and Aziz, Tarek}, year={2016}, month={Jul}, pages={602–610} }
 @article{line_osmond_childres_2016, title={Effectiveness of Livestock Exclusion in a Pasture of Central North Carolina}, volume={45}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2016.03.0089}, abstractNote={Reducing the export of nitrogen (N), phosphorus (P), and sediment from agricultural land in water‐supply watersheds is a continuing goal in central North Carolina. The objective of this project was to document the effectiveness of a combination of livestock exclusion fencing and nutrient management implemented on a beef cattle pasture located in the Piedmont region of North Carolina. The quantity and quality of discharge from two predominantly pasture watersheds were monitored simultaneously for 3.8 yr before and after implementation of the exclusion fencing and nutrient management in the treatment watershed; a control watershed remained unchanged. The excluded stream corridor was intentionally minimized by constructing the fence line about 3 m from the top of the streambank on either side and limiting it to the main stream channel only. Monitoring included collecting flow‐proportional samples during storm events and analyzing them for total Kjeldahl N (TKN), ammonia (NH3–N), and inorganic (NOx–N) N as well as total P (TP) and total suspended solids (TSS). Statistically significant reductions were observed in TKN (34%), NH3–N (54%), TP (47%), and TSS (60%) loads in the treatment relative to the control watershed after fencing, whereas storm discharge and NOx–N loads were not significantly different. These data show that even a relatively narrow exclusion corridor implemented on only the main stream channel can significantly reduce the export of N, P, and sediment from a beef cattle pasture.Core Ideas
Document, through water quality monitoring, the effectiveness of livestock exclusion fencing
Livestock exclusion reduced nitrogen, phosphorus, and sediment export from a pasture.
Statistical analysis is required to assess trends in water quality monitoring data.
}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Line, Daniel E. and Osmond, Deanna L. and Childres, Wesley}, year={2016}, pages={1926–1932} }
 @article{davidson_nifong_ferguson_palm_osmond_baron_2016, title={Nutrients in the nexus}, volume={6}, ISSN={2190-6483 2190-6491}, url={http://dx.doi.org/10.1007/S13412-016-0364-Y}, DOI={10.1007/S13412-016-0364-Y}, abstractNote={Synthetic nitrogen (N) fertilizer has enabled modern agriculture to greatly improve human nutrition during the twentieth century, but it has also created unintended human health and environmental pollution challenges for the twenty-first century. Averaged globally, about half of the fertilizer-N applied to farms is removed with the crops, while the other half remains in the soil or is lost from farmers' fields, resulting in water and air pollution. As human population continues to grow and food security improves in the developing world, the dual development goals of producing more nutritious food with low pollution will require both technological and socio-economic innovations in agriculture. Two case studies presented here, one in sub-Saharan Africa and the other in Midwestern United States, demonstrate how management of nutrients, water, and energy is inextricably linked in both small-scale and large-scale food production, and that science-based solutions to improve the efficiency of nutrient use can optimize food production while minimizing pollution. To achieve the needed large increases in nutrient use efficiency, however, technological developments must be accompanied by policies that recognize the complex economic and social factors affecting farmer decision-making and national policy priorities. Farmers need access to affordable nutrient supplies and support information, and the costs of improving efficiencies and avoiding pollution may need to be shared by society through innovative policies. Success will require interdisciplinary partnerships across public and private sectors, including farmers, private sector crop advisors, commodity supply chains, government agencies, university research and extension, and consumers.}, number={1}, journal={Journal of Environmental Studies and Sciences}, publisher={Springer Science and Business Media LLC}, author={Davidson, Eric A. and Nifong, Rachel L. and Ferguson, Richard B. and Palm, Cheryl and Osmond, Deanna L. and Baron, Jill S.}, year={2016}, month={Feb}, pages={25–38} }
 @article{motallebi_o'connell_hoag_osmond_2016, title={Role of Conservation Adoption Premiums on Participation in Water Quality Trading Programs}, volume={8}, ISSN={["2073-4441"]}, DOI={10.3390/w8060245}, abstractNote={Over half of lakes, reservoirs, and ponds in the United States are threatened or impaired, mostly by nutrients. One policy to improve water quality is water quality trading (WQT). While the concept is appealing, adoption of conservation practices in these programs has been anemic at best. Using a case study in the newly-formed WQT market in Jordan Lake, North Carolina, we propose that part of the problem is a large adoption premium (AP) for this program. AP is the amount that farmers require over and above direct adoption costs to participate. In this study, farmers were asked at in-person interviews about their willingness to accept (WTA) a payment to adopt a particular conservation practice (riparian buffers) in order to generate and sell credits. We compared farmers’ WTA to their direct cost of participation, which allowed us to estimate an AP. On average, the AP more than doubles the cost of purchasing credits. The AP sums all of the known indirect costs already cited in the literature, and more, into a single value and is relatively simple to estimate. Knowing the AP would improve the ability of policy makers to accurately estimate what is needed to boost adoption rates in WQT programs and other conservation programs as well.}, number={6}, journal={WATER}, author={Motallebi, Marzieh and O'Connell, Caela and Hoag, Dana L. and Osmond, Deanna L.}, year={2016}, month={Jun} }
 @article{huang_mackay_2016, title={The Genetic architecture of quantitative traits cannot be inferred from variance component analysis}, volume={12}, DOI={10.1101/041434}, abstractNote={AbstractClassical quantitative genetic analyses estimate additive and non-additive genetic and environmental components of variance from phenotypes of related individuals. The genetic variance components are defined in terms of genotypic values reflecting underlying genetic architecture (additive, dominance and epistatic genotypic effects) and allele frequencies. However, the dependency of the definition of genetic variance components on the underlying genetic models is not often appreciated. Here, we show how the partitioning of additive and non-additive genetic variation is affected by the genetic models and parameterization of allelic effects. We show that arbitrarily defined variance components often capture a substantial fraction of total genetic variation regardless of the underlying genetic architecture in simulated and real data. Therefore, variance component analysis cannot be used to infer genetic architecture of quantitative traits. The genetic basis of quantitative trait variation in a natural population can only be defined empirically using high resolution mapping methods followed by detailed characterization of QTL effects.}, number={11}, journal={PLoS Genetics}, author={Huang, W. and Mackay, T. F. C.}, year={2016} }
 @article{spence_walker_robarge_preston_osmond_2015, title={Comparing nitrous oxide losses from three residential landscapes under different management schemes following natural rainfall events}, volume={18}, ISSN={["1573-1642"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84949200350&partnerID=MN8TOARS}, DOI={10.1007/s11252-015-0453-9}, number={4}, journal={URBAN ECOSYSTEMS}, author={Spence, Porche L. and Walker, John T. and Robarge, Wayne P. and Preston, Bill and Osmond, Deanna L.}, year={2015}, month={Dec}, pages={1227–1243} }
 @article{edgell_osmond_line_hoyt_grossman_larsen_2015, title={Comparison of Surface Water Quality and Yields from Organically and Conventionally Produced Sweet Corn Plots with Conservation and Conventional Tillage}, volume={44}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2015.02.0074}, abstractNote={Organic agricultural systems are often assumed to be more sustainable than conventional farming, yet there has been little work comparing surface water quality from organic and conventional production, especially under the same cropping sequence. Our objective was to compare nutrient and sediment losses, as well as sweet corn ( L. var. ) yield, from organic and conventional production with conventional and conservation tillage. The experiment was located in the Appalachian Mountains of North Carolina. Four treatments, replicated four times, had been in place for over 18 yr and consisted of conventional tillage (chisel plow and disk) with conventional production (CT/Conven), conservation no-till with conventional production (NT/Conven), conventional tillage with organic production (CT/Org), and conservation no-till with organic production (NT/Org). Water quality (surface flow volume; nitrogen, phosphorus, and sediment concentrations) and sweet corn yield data were collected in 2011 and 2012. Sediment and sediment-attached nutrient losses were influenced by tillage and cropping system in 2011, due to higher rainfall, and tillage in 2012. Soluble nutrients were affected by the nutrient source and rate, which are a function of the cropping system. Sweet corn marketable yields were greater in conventional systems due to high weed competition and reduced total nitrogen availability in organic treatments. When comparing treatment efficiency (yield kg ha /nutrient loss kg ha ), the NT/Conven treatment had the greatest sweet corn yield per unit of nutrient and sediment loss. Other treatment ratios were similar to each other; thus, it appears the most sustainably productive treatment was NT/Conven.}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Edgell, Joshua and Osmond, D. L. and Line, D. E. and Hoyt, G. D. and Grossman, J. M. and Larsen, E. M.}, year={2015}, pages={1861–1870} }
 @article{morse_walter_osmond_hunt_2016, title={Roadside soils show low plant available zinc and copper concentrations}, volume={209}, ISSN={["1873-6424"]}, DOI={10.1016/j.envpol.2015.11.011}, abstractNote={Vehicle combustion and component wear are a major source of metal contamination in the environment, which could be especially concerning where road ditches are actively farmed. The objective of this study was to assess how site variables, namely age, traffic (vehicles day(-1)), and percent carbon (%C) affect metal accumulation in roadside soils. A soil chronosequence was established with sites ranging from 3 to 37 years old and bioavailable, or mobile, concentrations of Zinc (Zn) and Copper (Cu) were measured along major highways in North Carolina using a Mehlich III extraction. Mobile Zn and Cu concentrations were low overall, and when results were scaled via literature values to "total metal", the results were still generally lower than previous roadside studies. This could indicate farming on lands near roads would pose a low plant toxicity risk. Zinc and Cu were not correlated with annual average traffic count, but were positively correlated with lifetime traffic load (the product of site age and traffic count). This study shows an often overlooked variable, site age, should be included when considering roadside pollution accumulation. Zinc and Cu were more strongly associated with %C, than traffic load. Because vehicle combustion is also a carbon source, it is not obvious whether the metals and carbon are simply co-accumulating or whether the soil carbon in roadside soils may facilitate previously overlooked roles in sequestering metals on-site.}, journal={ENVIRONMENTAL POLLUTION}, author={Morse, Natalie and Walter, M. Todd and Osmond, Deanna and Hunt, William}, year={2016}, month={Feb}, pages={30–37} }
 @article{bordeaux_grossman_white_osmond_poore_pietrosemoli_2014, title={Effects of rotational infrastructure within pasture-raised pig operations on ground cover, soil nutrient distribution, and bulk density}, volume={69}, ISSN={["1941-3300"]}, DOI={10.2489/jswc.69.2.120}, abstractNote={Interest in pasture-based pork products has increased significantly in recent years. However, nitrogen (N) losses resulting from these systems are common due to importation of feed, high stocking rates, and pig behavior. This study was conducted to evaluate soil inorganic N, soil-test phosphorus (STP), ground cover, and compaction changes as impacted by rotational shade, water, and feed structures in a pasture-raised pig operation over two 12-week pig occupations. Shade and watering structures were rotated weekly for 12 weeks within a rotational (mobile) scheme; data were compared to a stationary structure system as well as to a managed hay operation with no pigs. Soil samples were acquired from subplots and analyzed for distribution of inorganic N concentrations among main plot treatments, including nitrate (NO3), ammonium (NH4), and STP values. Soil inorganic N concentrations were higher in exterior subplot positions than in interior positions. This pattern was not maintained after a second pig group occupied the plots. Soil test phosphorus was unaffected by either pig occupation. Ground cover percentages were higher in control (hay) treatments than for pig treatments, however no difference was found between mobile and stationary structure treatments in either pig occupation. Soil compaction, as measured by soil bulk density, was found to be higher under permanent shade structure locations as compared to mobile and control treatments. Mobile and control compaction levels were not different for the second occupation, utilizing a more intensive sampling scheme, suggesting a benefit to the rotation of shade, water and feed infrastructure. The weekly rotation of infrastructure performed during both occupations was both labor intensive and time consuming. The observed lack of improvement in nutrient distribution to a rotational infrastructure may limit its utility in pastured-pig systems. However, further options are available that would allow the production of pasture-raised pigs while minimizing associated nutrient loading and pasture degradation.}, number={2}, journal={JOURNAL OF SOIL AND WATER CONSERVATION}, publisher={Soil and Water Conservation Society}, author={Bordeaux, C. and Grossman, J. and White, J. and Osmond, D. and Poore, M. and Pietrosemoli, S.}, year={2014}, pages={120–130} }
 @article{osmond_hoag_luloff_meals_neas_2015, title={Farmers' Use of Nutrient Management: Lessons from Watershed Case Studies}, volume={44}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2014.02.0091}, abstractNote={Nutrient enrichment of water resources has degraded coastal waters throughout the world, including in the United States (e.g., Chesapeake Bay, Gulf of Mexico, and Neuse Estuary). Agricultural nonpoint sources have significant impacts on water resources. As a result, nutrient management planning is the primary tool recommended to reduce nutrient losses from agricultural fields. Its effectiveness requires nutrient management plans be used by farmers. There is little literature describing nutrient management decision-making. Here, two case studies are described that address this gap: (i) a synthesis of the National Institute of Food and Agriculture, the Conservation Effects Assessment Project, and (ii) field surveys from three nutrient-impaired river basins/watersheds in North Carolina (Neuse, Tar-Pamlico, and Jordan Lake drainage areas). Results indicate farmers generally did not fully apply nutrient management plans or follow basic soil test recommendations even when they had them. Farmers were found to be hesitant to apply N at university-recommended rates because they did not trust the recommendations, viewed abundant N as insurance, or used recommendations made by fertilizer dealers. Exceptions were noted when watershed education, technical support, and funding resources focused on nutrient management that included easing management demands, actively and consistently working directly with a small group of farmers, and providing significant resource allocations to fund agency personnel and cost-share funds to farmers. Without better dialogue with farmers and meaningful investment in strategies that reward farmers for taking what they perceive as risks relative to nutrient reduction, little progress in true adoption of nutrient management will be made.}, number={2}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Osmond, Deanna L. and Hoag, Dana L. K. and Luloff, Al E. and Meals, Donald W. and Neas, Kathy}, year={2015}, pages={382–390} }
 @article{wiseman_burchell_grabow_osmond_messer_2014, title={GROUNDWATER NITRATE CONCENTRATION REDUCTIONS IN A RIPARIAN BUFFER ENROLLED IN THE NC CONSERVATION RESERVE ENHANCEMENT PROGRAM}, volume={50}, ISSN={["1752-1688"]}, DOI={10.1111/jawr.12209}, abstractNote={AbstractRiparian buffers have been used for many years as a best management practice to decrease the effects of nonpoint pollution from watersheds. The NC Conservation Reserve Enhancement Program (NC CREP) has established buffers to treat groundwater nitrate‐nitrogen (NO3−‐N) from agricultural sources in multiple river basins. A maturing 46 m wide riparian buffer enrolled in NC CREP was studied to determine its effectiveness in reducing groundwater NO3−‐N concentrations from a cattle pasture fertilized with poultry litter. Three monitoring blocks that included groundwater quality wells, water table wells, and soil redox probes, were established in the buffer. NO3−‐N concentrations decreased significantly across the buffer in all of the monitoring blocks with mean reductions of 76‐92%. Many biological processes, including denitrification and plant uptake, may have been responsible for the observed NO3−‐N reductions but could not be differentiated in this study. However, mean reductions in Cl− concentrations ranged from 48‐65% through the blocks, which indicated that dilution was an important factor in observed NO3−‐N reductions. These findings should be carefully considered for future buffer enrollments when assigning nitrogen removal credits.}, number={3}, journal={JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION}, author={Wiseman, Jacob D. and Burchell, Michael R. and Grabow, Garry L. and Osmond, Deanna L. and Messer, T. L.}, year={2014}, month={Jun}, pages={653–664} }
 @article{larsen_grossman_edgell_hoyt_osmond_hu_2014, title={Soil biological properties, soil losses and corn yield in long-term organic and conventional farming systems}, volume={139}, ISSN={["1879-3444"]}, DOI={10.1016/j.still.2014.02.002}, abstractNote={Topsoil losses through surface runoff have severe implications for farmers, as well as surrounding ecosystems and waterbodies. However, integrating management systems that enhance soil organic matter (SOM) can stabilize the soil surface from erosion. Little is known about how differences in both tillage and cropping system management affect carbon and subsequent sediment losses in horticultural fields, particularly in the humid climate of the southeast. Research was conducted in the Appalachian Mountains in Mills River, NC on a fine-sandy loam Acrisol from 2010 to 2012 on long-term plots established in 1994. Project objectives included to: (1) quantify labile and total organic matter based on tillage and cropping system practices, (2) determine if relationships exist between SOC ad sediment losses, and (3) determine long-term management and tillage impacts on total organic matter lost via runoff. We hypothesized that organic management and reduced tillage would lead to increased soil carbon, which subsequently reduce losses as soil is stabilized. Organic no tillage and conventional till treatments contained on average 14.34 and 6.80 g kg−1 total carbon (TC) respectively, with the organic no till treatments containing twice the quantity of TC and light fraction particulate organic matter (LPOM) in the upper 15 cm as compared with the conventionally tilled treatments, and four times the quantity of microbial biomass carbon (MBC). LPOM and HPOM, the heavier fraction of POM, did not differ in the organic till and conventional no till treatments.Data support our hypothesis that organic production in combination with no tillage increases C pools (both total and labile) as compared with tilled conventional plots. However, organic no till treatments produced sweet corn (Zea mays var. saccharata) yields less than 50% of that of conventional treatments, attributed to weed competition and lack of available N. No tillage treatments lost two to four times less soil C via surface runoff than tilled systems. Additionally, we found that as total soil C increased, suspended solids lost through surface runoff decreased. Overall, our results indicate tillage to be an important factor in enhancing soil C and decreasing soil loss through surface runoff.}, journal={SOIL & TILLAGE RESEARCH}, author={Larsen, Erika and Grossman, Julie and Edgell, Joshua and Hoyt, Greg and Osmond, Deanna and Hu, Shuijin}, year={2014}, month={Jun}, pages={37–45} }
 @article{woods_luloff_osmond_hoag_2014, title={Toward a Synthesis: Lessons from Thirteen Cropland Watershed-Scale Studies}, volume={27}, ISSN={["1521-0723"]}, DOI={10.1080/08941920.2013.861551}, abstractNote={To integrate lessons from the U.S. Department of Agriculture (USDA), National Institute of Food and Agriculture–Conservation Effects Assessment Project (NIFA CEAP) program, key informant (KI) interviews were conducted in all 13 project areas. The purpose of these interviews was to supplement technical information about watersheds, their contaminants, modeling, economics, and key findings. We interviewed a wide range of people to develop a systematic look at individual project results, synthesize meanings, and derive principles useful in guiding future watershed management. Findings revealed common themes, which tended to align with KI categories, regardless of location. For instance, farmers and ranchers often understood water quality problems as well as federal and state personnel and university employees do. Conservation adoption by farmers was related to perceived need, cost, and convenience of the practice, as well as practice specifics and individual situations. Possible implications of these findings are advanced.}, number={4}, journal={SOCIETY & NATURAL RESOURCES}, author={Woods, Brad R. and Luloff, A. E. and Osmond, Deanna and Hoag, Dana}, year={2014}, month={Apr}, pages={341–357} }
 @article{gold_parker_waskom_dobrowolski_m. o'neill_groffman_addy_barber_batie_benham_et al._2013, title={Advancing water resource management in agricultural, rural, and urbanizing watersheds: Why land-grant universities matter}, volume={68}, ISSN={["1941-3300"]}, DOI={10.2489/jswc.68.4.337}, abstractNote={Federally funded university water programs have had limited success in halting the degradation of water resources in agricultural, rural, and urbanizing watersheds for the past five decades. USDA-funded university water programs have advanced our understanding of watershed processes and the development of best management practices (BMPs; e.g., conservation tillage, nutrient management, alternative and innovative septic systems, and riparian buffers) to mitigate environmental risks from anthropogenic activities, in particular from agriculture, to our water resources; yet water degradation persists and has worsened in many watersheds (Howarth et al. 2000; Mueller and Spahr 2006). The National Research Council (2012) stresses the need for sustainable agricultural practices to reduce changes in flow regimes and water quality. In this research editorial, we make four points relative to solving water resource issues: (1) they are complex problems and difficult to solve; (2) some progress has been made on solving these issues; (3) external nonstationary drivers such as land use changes, climate change and variability, and shifts in markets, policies, and regulations warrant constant vigilance to assure that presumed improvements are being attained; and (4) we are poised to make substantial progress on these challenges over the next 10 to 20 years if critical steps are…}, number={4}, journal={JOURNAL OF SOIL AND WATER CONSERVATION}, author={Gold, A. J. and Parker, D. and Waskom, R. M. and Dobrowolski, J. and M. O'Neill and Groffman, P. M. and Addy, K. and Barber, M. and Batie, S. and Benham, B. and et al.}, year={2013}, pages={337–348} }
 @article{bouchard_osmond_winston_hunt_2013, title={The capacity of roadside vegetated filter strips and swales to sequester carbon}, volume={54}, ISSN={["1872-6992"]}, DOI={10.1016/j.ecoleng.2013.01.018}, abstractNote={Carbon capture and storage within vegetation and soil is impacted by changing land uses, which results in either a net source or sink of greenhouse gases (GHGs) to the atmosphere. Transportation corridors are present world-wide, and the vegetated filter strip and vegetated swale (VFS/VS), a common stormwater control measure, often constitutes the right-of-way (ROW) adjacent to roadways. The roadway environment, specifically carbon pools in North Carolina highway ROWs, were studied for carbon sequestration potential, an important ecosystem service. The study was conducted in two North Carolina physiographic regions: the Piedmont (characterized by clay-influenced soils) and the Coastal Plain (predominantly sandy soils). Approximately 700 soil samples were collected in VFS/VSs and wetland swales alongside major highways and analyzed for percent total soil C (% total C) and bulk density to obtain the C density. Mean soil C densities (per unit area) were 2.55 ± 0.13 kg C m−2 (mean ± standard error, n = 160, 0.2 m sample depth) in the Piedmont and 4.14 ± 0.15 kg C m−2 (n = 160, 0.2 m depth) in Coastal Plain highway VFS/VSs. Previous studies on grasslands had similar C density values to those observed in this study; thus, grasslands could be a surrogate land use for highway VFS/VSs. A thirty-seven year soil chronosequence characterized C accumulation in Piedmont VFS/VSs. Carbon density increases showed an association with age in Piedmont VFS/VSs only, which were calculated to reach maximum C density of 3.34 kg C m−2, at age = 21.5 years. Previous studies on grasslands show similar C density and accumulation values to those observed in this study; thus, again grasslands could be a surrogate land use for highway VFS/VSs. Carbon density did not differ between dry or wetland swales, although % total C was significantly greater in wetland swales. The mean VS C density was 3.05 ± 0.13 kg C m−2 (n = 40, 0.2 m depth), while that for wetland swales was 5.04 ± 0.73 kg C m−2 (n = 44, 0.2 m depth). To promote C sequestration in the vegetated ROW, wetland swales appear preferable to dry swales.}, journal={ECOLOGICAL ENGINEERING}, author={Bouchard, Natalie R. and Osmond, Deanna L. and Winston, Ryan J. and Hunt, William F.}, year={2013}, month={May}, pages={227–232} }
 @article{spence_osmond_childres_heitman_robarge_2012, title={Effects of Lawn Maintenance on Nutrient Losses Via Overland Flow During Natural Rainfall Events}, volume={48}, ISSN={1093-474X}, url={http://dx.doi.org/10.1111/j.1752-1688.2012.00658.x}, DOI={10.1111/j.1752-1688.2012.00658.x}, abstractNote={Spence, Porchè L., Deanna L. Osmond, Wesley Childres, Joshua L. Heitman, and Wayne P. Robarge, 2012. Effects of Lawn Maintenance on Nutrient Losses Via Overland Flow During Natural Rainfall Events. Journal of the American Water Resources Association (JAWRA) 48(5): 909‐924. DOI: 10.1111/j.1752‐1688.2012.00658.xAbstract:  A sampling system was used to evaluate the effect of residential lawn management on nutrient losses via overland flow generated during natural rainfall events from three residential landscapes: a high maintenance fescue lawn (HMFL), a low maintenance fescue lawn (LMFL), and a mixed forested residential landscape (FRL). A sampling system was located in designated areas within each landscape such that 100% of the runoff follows natural flow paths to the outlet ports and collects in sterile Nalgene® B3 media bags (Thermo Fisher Scientific, Rochester, NY). A rainfall event was defined as producing ≥2.54 mm of water. A total of 87 rainfall events occurred during a 20‐month monitoring period. The total runoff volume collected from the LMFL was higher than from the HMFL and FRL, but on average <1% of the total rainfall was collected from the three landscapes. Mean nitrate concentrations from each lawn did not exceed 0.6 mg N/l. Nutrient unit area losses from the HMFL, LMFL, and FRL were 1,000 times less than fertilizer and throughfall inputs, which were due to the presence of well‐structured soils (low bulk densities) with high infiltration rates. This study demonstrated that the frequency of runoff, total runoff volumes, and nutrient losses during natural rainfall events are lower from highly maintained (i.e., irrigation, fertilizer application, and reseeding) densely uniform manicured lawns than low maintenance lawns and forested residential landscapes.}, number={5}, journal={JAWRA Journal of the American Water Resources Association}, publisher={Wiley}, author={Spence, Porchè L. and Osmond, Deanna L. and Childres, Wesley and Heitman, Joshua L. and Robarge, Wayne P.}, year={2012}, month={May}, pages={909–924} }
 @article{messer_burchell_grabow_osmond_2012, title={Groundwater nitrate reductions within upstream and downstream sections of a riparian buffer}, volume={47}, ISSN={["1872-6992"]}, DOI={10.1016/j.ecoleng.2012.06.017}, abstractNote={The objective of this study was to evaluate the water quality benefits provided by a buffer enrolled in the North Carolina Conservation Reserve Enhancement Program (NC CREP). A 5-year study was conducted on two distinct buffer sections along the same stream to evaluate the hydrology and attenuation of groundwater nitrate (NO3−-N) entering from nearby agricultural fields. The average buffer widths were 60 m (Section 1, upstream) and 45 m (Section 2, downstream). Three transects of groundwater monitoring well nests within each buffer zone were installed to monitor water quality and water table depths for 5 years. Mean groundwater NO3−-N concentrations at the 1.5 m depth decreased from 4.5 mg L−1 to 1.7 mg L−1 and from 12.9 mg L−1 to 1.4 mg L−1 in buffer Sections 1 and 2 respectively. These differences were significant in both buffer sections (α = 0.05), but the wider Section 1 received significantly less NO3−-N than did Section 2 (P < 0.0001). Groundwater NO3−-N loads were reduced by 0.003 kg m−2 yr−1 (76% reduction) at the 1.5 m depth, while in Section 2 these loads were reduced by 0.02 kg m−2 yr−1 (94% reduction) and 0.04 kg m−2 yr−1 (86% reduction) at the 1.5 m and 3 m depths, respectively. Topography, water table and redox measurements, nitrate to chloride ratios, and deep groundwater cation analyses, indicated both sections were suitable for denitrification to proceed. However, the position of the wider Section 1 buffer in the landscape limited the amount of NO3−-N contaminated groundwater that entered from the agricultural fields, and thus could have been designed to be narrower. The effectiveness of NO3−-N reduction in riparian buffer systems is dependent on multiple landscape and biogeochemical factors and not buffer width alone. Findings provide design guidance for conservation buffer program managers as related to the influence of buffer landscape position on groundwater nitrate reduction.}, journal={ECOLOGICAL ENGINEERING}, author={Messer, Tiffany L. and Burchell, Michael R., II and Grabow, Garry L. and Osmond, Deanna L.}, year={2012}, month={Oct}, pages={297–307} }
 @article{osmond_meals_hoag_arabi_luloff_jennings_mcfarland_spooner_sharpley_line_2012, title={Improving conservation practices programming to protect water quality in agricultural watersheds: Lessons learned from the National Institute of Food and Agriculture-Conservation Effects Assessment Project}, volume={67}, ISSN={["1941-3300"]}, DOI={10.2489/jswc.67.5.122a}, abstractNote={Nutrient enrichment and sedimentation of water resources is a significant problem in the United States and globally (Carpenter et al. 2011; Dubrovsky et al. 2010; Hilton et al. 2006). Specifically, in the United States, over 6,908 water bodies are listed as being nutrient impaired and 6,165 are sediment impaired (USEPA 2012). Agricultural nonpoint source pollution contributes, in part, to impaired water resources in many of these watersheds (NRC 2008; USEPA 2010). Conservation practices, including conservation tillage, nutrient management, and riparian buffers, are routinely used to reduce off-site losses of sediment, nutrients, pesticides, and bacteria from agricultural operations. Many research studies, generally conducted at the plot- or field-scale, report ranges in effectiveness of such conservation practices, from being negative to 100% effective (Gagnon et al. 2004; Gagnon et al. 2008; Jokela et al. 2004; Line et al. 2001; Richards and Baker 2002; Schnepf and Cox 2006; Sharpley et al. 2006; Shepard 2005; Smith et al. 2006). Documentation of combined practice impacts on water quality at the watershed scale has been more difficult than in plot or field-scale studies. The Black Creek Project in northeastern Indiana and the Model Implementation Program (MIP) promoted by the USDA and US Environmental Protection Agency (USEPA)…}, number={5}, journal={JOURNAL OF SOIL AND WATER CONSERVATION}, author={Osmond, Deanna and Meals, Don and Hoag, Dana and Arabi, Mazdak and Luloff, Al and Jennings, Greg and McFarland, Mark and Spooner, Jean and Sharpley, Andrew and Line, Dan}, year={2012}, pages={122A–127A} }
 @article{wu_osmond_graves_burchell_duckworth_2012, title={Relationships Between Nitrogen Transformation Rates and Gene Abundance in a Riparian Buffer Soil}, volume={50}, ISSN={0364-152X 1432-1009}, url={http://dx.doi.org/10.1007/s00267-012-9929-z}, DOI={10.1007/s00267-012-9929-z}, abstractNote={Denitrification is a critical biogeochemical process that results in the conversion of nitrate to volatile products, and thus is a major route of nitrogen loss from terrestrial environments. Riparian buffers are an important management tool that is widely utilized to protect water from non-point source pollution. However, riparian buffers vary in their nitrate removal effectiveness, and thus there is a need for mechanistic studies to explore nitrate dynamics in buffer soils. The objectives of this study were to examine the influence of specific types of soluble organic matter on nitrate loss and nitrous oxide production rates, and to elucidate the relationships between these rates and the abundances of functional genes in a riparian buffer soil. Continuous-flow soil column experiments were performed to investigate the effect of three types of soluble organic matter (citric acid, alginic acid, and Suwannee River dissolved organic carbon) on rates of nitrate loss and nitrous oxide production. We found that nitrate loss rates increased as citric acid concentrations increased; however, rates of nitrate loss were weakly affected or not affected by the addition of the other types of organic matter. In all experiments, rates of nitrous oxide production mirrored nitrate loss rates. In addition, quantitative polymerase chain reaction (qPCR) was utilized to quantify the number of genes known to encode enzymes that catalyze nitrite reduction (i.e., nirS and nirK) in soil that was collected at the conclusion of column experiments. Nitrate loss and nitrous oxide production rates trended with copy numbers of both nir and 16s rDNA genes. The results suggest that low-molecular mass organic species are more effective at promoting nitrogen transformations than large biopolymers or humic substances, and also help to link genetic potential to chemical reactivity.}, number={5}, journal={Environmental Management}, publisher={Springer Science and Business Media LLC}, author={Wu, Lin and Osmond, Deanna L. and Graves, Alexandria K. and Burchell, Michael R. and Duckworth, Owen W.}, year={2012}, month={Aug}, pages={861–874} }
 @article{johnson_burchell_evans_osmond_gilliam_2013, title={Riparian buffer located in an upland landscape position does not enhance nitrate-nitrogen removal}, volume={52}, ISSN={0925-8574}, url={http://dx.doi.org/10.1016/j.ecoleng.2012.11.006}, DOI={10.1016/j.ecoleng.2012.11.006}, abstractNote={Relatively narrow (<50 m) riparian buffers strategically reestablished in correct landscape positions have been shown to significantly reduce agricultural non-point source pollution to streams. Because of this, conservation programs have been established to encourage landowners to enroll lands near surface waters to improve water quality. Former cropland enrolled in a conservation program was evaluated to determine its effectiveness in reducing nitrate-nitrogen (NO3−-N) in shallow groundwater. This conservation buffer (CB) was up to 80 m wide and was planted with loblolly pine (Pinus taeda). It was situated upslope of an existing 30–60 m wide riparian hardwood forest buffer (EHB) located within the floodplain of an intermittent stream. Shallow groundwater NO3−-N, groundwater hydrology, total organic carbon, and soil redox potential were measured throughout both the CB and the EHB for 18 months. Groundwater NO3−-N concentrations, often 5–15 mg L−1 within the CB, were not significantly reduced from concentrations that entered from the agricultural field edge. However, a decrease in NO3−-N concentration was observed within the EHB (17–83%). The hydrology of the CB coupled with relatively low organic carbon contributed to a low denitrification potential and lack of NO3−-N reduction compared with the EHB. While the CB enrollment likely provided additional habitat benefits it did not appear to provide treatment of groundwater NO3−-N. It is our conclusion that landscape position is a more important defining variable for buffer site selection than buffer width if NO3−-N reduction is a primary goal.}, journal={Ecological Engineering}, publisher={Elsevier BV}, author={Johnson, Sara R. and Burchell, Michael R., II and Evans, Robert O. and Osmond, Deanna L. and Gilliam, J. Wendell}, year={2013}, month={Mar}, pages={252–261} }
 @article{kang_amoozegar_hesterberg_osmond_2011, title={Phosphorus leaching in a sandy soil as affected by organic and inorganic fertilizer sources}, volume={161}, ISSN={["0016-7061"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79951581004&partnerID=MN8TOARS}, DOI={10.1016/j.geoderma.2010.12.019}, abstractNote={Long-term application of phosphorus (P) to soils as fertilizer or manure can increase the potential for P loss to ground and surface waters. Vertical P transport was investigated in a sandy soil material receiving seven different P fertilizer sources: poultry compost, poultry litter, triple superphosphate [Ca(H2PO4)2·H2O], dairy lagoon liquid, swine lagoon liquid, swine lagoon sludge, and dissolved potassium dihydrogen phosphate (KH2PO4). The P sources were surface-applied to soil columns (6.35-cm diameter, 10-cm long) at two rates equivalent to 75 and 150 kg total P ha−1, and columns were intermittently leached with deionized (DI) water. Column effluents were collected for up to 23 pore volumes and analyzed for dissolved reactive phosphorus (DRP) and dissolved organic carbon (DOC). In addition, a P retardation factor was determined for the soil from a P adsorption isotherm. Transport of P through soil columns receiving liquid P sources was simulated by a one-dimensional equilibrium convective–dispersive equation (CDE) based on water-extractable P (WEP) concentrations. Cumulative amounts of DRP leached were linearly related to the amounts of WEP in P source materials (r2 = 0.87***). The recovery of DRP in the column effluents relative to WEP in the applied materials was 126 ± 15% (mean ± standard error) for organic P sources and 66 ± 2% for inorganic P sources. The use of WEP in the CDE model underpredicted P transport in the columns amended with lagoon liquids compared with dissolved KH2PO4. Results indicated that leaching losses of P from land-applied manures exceed the amounts of WEP in source materials because of organic P mineralization and competitive sorption of DOC.}, number={3-4}, journal={GEODERMA}, author={Kang, Jihoon and Amoozegar, Aziz and Hesterberg, Dean and Osmond, Deanna L.}, year={2011}, month={Mar}, pages={194–201} }
 @article{cahill_osmond_weisz_heiniger_2010, title={Evaluation of Alternative Nitrogen Fertilizers for Corn and Winter Wheat Production}, volume={102}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2010.0095}, abstractNote={As natural gas, and thus N fertilizer, prices increase, farmers are looking for ways to decrease N costs in farming operations. To potentially alleviate this cost burden, alternative synthetic N fertilizers are available as potential management tools for increasing crop yields and N use efficiency, and decreasing volatilization. In North Carolina specifically, little data exists on these new, synthetic N fertilizer products being marketed to farmers. Therefore, we undertook a study to compare them with aqueous urea ammonium nitrate (UAN) [(NH2)2CO, NH4NO3] during a 2‐yr field experiment. Corn (Zea mays L.) and wheat (Triticum aestivum L.) were grown in the three physiographic regions of North Carolina with four fertilizer sources (NutriSphere [Specialty Fertilizer Products, Leawood, KS], Environmentally Smart Nitrogen Polymer Coated Urea or ESN [Agrium Inc., Alberta, Canada] UCAN‐23 [Yara, Tampa, FL], and UAN) at up to six fertilizer rates. The use of the alternative products did not regularly produce more corn or wheat grain compared to UAN, while wheat straw yield was greater with NutriSphere, UCAN, and UAN compared to ESN in three of four site years. Also, an aerobic incubation experiment was performed to evaluated N release profiles of the fertilizers at 25°C. The study found that NutriSphere and UCAN release time was similarly to UAN, while ESN showed a slower release profile. However, any difference in release did not affect yields of spring planted corn, NutriSphere and ESN increased corn stover yields in 3 of 6 site‐years. In determining whether to use these alternative N fertilizer products, farmers should consider location, climatic conditions, and fertilizer costs in comparison to UAN.}, number={4}, journal={AGRONOMY JOURNAL}, author={Cahill, Sheri and Osmond, Deanna and Weisz, Randy and Heiniger, Ronnie}, year={2010}, pages={1226–1236} }
 @article{winston_hunt_osmond_lord_woodward_2011, title={Field Evaluation of Four Level Spreader-Vegetative Filter Strips to Improve Urban Storm-Water Quality}, volume={137}, ISSN={["1943-4774"]}, DOI={10.1061/(asce)ir.1943-4774.0000173}, abstractNote={An assessment of the performance of four level spreader–vegetative filter strip (LS-VFS) systems designed to treat urban storm-water runoff was undertaken at two sites in the Piedmont of North Carolina. At each site, a 7.6-m grassed filter strip and a 15.2-m half-grassed, half-forested filter strip were examined. Monitored parameters included rainfall, inflow to, and outflow from each LS-VFS system. A total of 21 and 22 flow-proportional water quality samples were collected and analyzed for the Apex and Louisburg sites, respectively. All studied LS-VFS systems significantly reduced mean total suspended solids (TSS) concentrations (p<0.05), with the 7.6 and 15.2-m buffers reducing TSS by at least 51 and 67%, respectively. Both 15.2-m VFSs significantly reduced the concentrations of total Kjeldahl nitrogen (TKN), total nitrogen (TN), organic nitrogen (Org-N), and NH4-N (p<0.05), whereas results were mixed for the 7.6-m VFSs. Significant pollutant mass reduction was observed (p<0.05) for all nine pollutant f...}, number={3}, journal={JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING}, author={Winston, R. J. and Hunt, William F., III and Osmond, D. L. and Lord, W. G. and Woodward, M. D.}, year={2011}, month={Mar}, pages={170–182} }
 @article{cahill_osmond_israel_2010, title={Nitrogen Release from Coated Urea Fertilizers in Different Soils}, volume={41}, ISSN={["1532-2416"]}, DOI={10.1080/00103621003721437}, abstractNote={The nitrogen (N) release from coated urea fertilizers (Arborite and ESN), traditional N fertilizers [urea, (NH2)2CO], and urea ammonium nitrate (UAN) [(NH2)2CO, NH4NO3] in three North Carolina (USA) soils was measured throughout a 12-week laboratory incubation. Treatments were N source and moisture level (60% and 80% of field capacity). In both the Candor and Cecil soils, 40% of the Arborite N had released by day 2 after addition to the soil. Maximum Arborite N release was achieved by week 6 for both soils. The ESN N release began between weeks 1 and 2, and maximum release was attained by week 6 for the Candor and by week 8 for the Cecil soil. The ESN reached 70% release on Portsmouth by week 8 and Arborite had an immediate release. Field studies of these coated ureas would be needed to determine if they are economically viable over more traditional N fertilizers in North Carolina.}, number={10}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, author={Cahill, Sheri and Osmond, Deanna and Israel, Daniel}, year={2010}, pages={1245–1256} }
 @article{osmond_nadkarni_driscoll_andrews_gold_allred_berkowitz_klemens_loecke_mcgarry_et al._2010, title={The role of interface organizations in science communication and understanding}, volume={8}, ISSN={["1540-9295"]}, DOI={10.1890/090145}, abstractNote={“Interface” organizations are groups created to foster the use of science in environmental policy, management, and education. Here we compare interface organizations that differ in spatial scale, modes of operation, and intended audience to illustrate their diversity and importance in promoting the application of science to environmental issues. There has been exciting recent growth in the nature and extent of activities by interface organizations and in new methods for science communication and engagement. These developments can help scientists – who face personal and institutional challenges when attempting to convey the results of their research to various audiences – interact with society on specific issues in specific places, and with a wide range of non‐traditional audiences. The ongoing mission for these organizations should be to move beyond simply increasing awareness of environmental problems to the creation of solutions that result in genuine environmental improvements.}, number={6}, journal={FRONTIERS IN ECOLOGY AND THE ENVIRONMENT}, author={Osmond, Deanna L. and Nadkarni, Nalini M. and Driscoll, Charles T. and Andrews, Elaine and Gold, Arthur J. and Allred, Shorna R. Broussard and Berkowitz, Alan R. and Klemens, Michael W. and Loecke, Terry L. and McGarry, Mary Ann and et al.}, year={2010}, month={Aug}, pages={306–313} }
 @article{osmond_cahill_schultheis_holmes_jester_2010, title={Tillage Practices and Nitrogen Rates on Pickling Cucumber Production}, volume={17}, ISSN={1931-5260 1931-5279}, url={http://dx.doi.org/10.1080/19315260.2010.499892}, DOI={10.1080/19315260.2010.499892}, abstractNote={Cucumbers require adequate nitrogen (N) for growth and development. This study was undertaken to determine the most effective tillage system and N rate for hand-picked, processing, cucumber (Cucumis sativus L.) production. Three tillage systems and five N fertilizer rates were compared for effects on yield, fertilizer N use efficiency (NUE), and effects on belly rot disease caused by Rhizoctonia solani. In both years conventional tillage had greater yields than no till and was greater than strip tillage one year. Cucumber NUE was not different between tillage systems or N rates; NUE averaged 35%. In one of two years, incidence of belly rot disease was greater under no till and increased with increasing N rate; in the other year, there was no affect of tillage on belly rot. In most years, conventional tillage for cucumbers will outperform strip tillage and no till.}, number={1}, journal={International Journal of Vegetable Science}, publisher={Informa UK Limited}, author={Osmond, Deanna L. and Cahill, Sheri L. and Schultheis, Jonathan R. and Holmes, Gerald J. and Jester, Wilfred R.}, year={2010}, month={Dec}, pages={13–25} }
 @article{osmond_2010, title={USDA water quality projects and the National Institute of Food and Agriculture Conservation Effects Assessment Project watershed studies INTRODUCTION}, volume={65}, ISSN={["0022-4561"]}, DOI={10.2489/jswc.65.6.142a}, abstractNote={The first major federally-funded effort to relate effects of conservation practices to water quality was the Black Creek Project in northeastern Indiana beginning in 1975 (USEPA 1977). From 1978 to 1982, United States Department of Agriculture (USDA) and US Environmental Protection Agency (USEPA) conducted the Model Implementation Program (MIP) to demonstrate and study the effects of addressing agricultural nonpoint source problems through Section 208 of the Clean Water Act (CWA) (NWQEP and Harbridge House 1983). Building on these early efforts, a much larger USDA- and USEPA-sponsored nonpoint source (NPS) pollution control program, The Rural Clean Water Program (RCWP), began in 1980 as an experiment to combine land treatment and water quality monitoring to document NPS control effectiveness across the country (Gale et al. 1993). The objectives of the RCWP were (1) to achieve improved water quality in the project area in the most cost-effective manner possible in keeping with the provision of adequate supplies of food, fiber, and a quality environment; (2) to assist agricultural landowners and operators in reducing agricultural NPS water pollutants and improving water quality in rural areas to meet water quality standards or water quality goals; and (3) to develop and test programs, policies, and procedures…}, number={6}, journal={JOURNAL OF SOIL AND WATER CONSERVATION}, author={Osmond, Deanna L.}, year={2010}, pages={142A–146A} }
 @article{kang_hesterberg_osmond_2009, title={Soil Organic Matter Effects on Phosphorus Sorption: A Path Analysis}, volume={73}, ISSN={["1435-0661"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-62549111344&partnerID=MN8TOARS}, DOI={10.2136/sssaj2008.0113}, abstractNote={While P sorption in mineral soils has been extensively studied, P sorption behavior in organic‐rich soils is less known. This study was conducted to determine the relationships between Langmuir P sorption maxima (Smax) and selected physicochemical properties of soils, with particular emphasis on organic matter (OM) content. The Smax values were determined for 72 soil samples from the North Carolina Coastal Plain, along with pH, clay and OM contents, oxalate‐extractable P (Pox), Al (Alox), and Fe (Feox), and Mehlich 3 extractable P (PM3), Al (AlM3), and Fe (FeM3). Path analysis was used to examine direct and indirect effects of soil properties on Smax In the oxalate path analysis, the direct effects of clay, Alox, and Feox on Smax were significant in the order Alox > clay > Feox (P < 0.05). The Smax was highly influenced by the indirect effect of Alox and Feox through OM content. A two‐piece segmented linear relationship existed between Smax and OM and the regression slope in soils with OM ≤ 49 g kg−1 was 10‐fold greater than that for soils with OM > 49 g kg−1 This finding suggested that noncrystalline or organically bound Al and Fe in the soils with OM > 49 g kg−1 is less effective for P sorption than in the soils with lower OM content. In the Mehlich 3 path analysis, the direct effects of clay, OM, and AlM3 on Smax were significant in the order AlM3 > OM > clay (P < 0.05) while the direct effect of FeM3 on Smax was not significant. Oxalate may be better suited than Mehlich 3 as an extractant for predicting P sorption capacity in the Coastal Plain soils.}, number={2}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Kang, Jihoon and Hesterberg, Dean and Osmond, Deanna L.}, year={2009}, pages={360–366} }
 @article{smith_osmond_moorman_stucky_gilliam_2008, title={Effect of vegetation management on bird habitat in Riparian buffer zones}, volume={7}, ISSN={["1938-5412"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-46149116795&partnerID=MN8TOARS}, DOI={10.1656/1528-7092(2008)7[277:EOVMOB]2.0.CO;2}, abstractNote={Abstract Riparian buffers can be valuable refuge areas for wildlife in otherwise homogeneous agricultural landscapes. Government sponsored programs like the Cropland Reserve Program generally require the planting of specific vegetative species during buffer restoration, although the effectiveness of such an approach when compared to restoration by volunteer species is unknown. We studied the effect of differences in vegetation structure on avian habitat in riparian buffer zones. A 25 m (82 ft) wide planted woodland buffer, 30 m (98 ft) wide grass, shrub, and woodland three-zone buffer, and a 9 m (30 ft) wide shrub buffer were evaluated for habitat potential using breeding-bird counts and vegetation surveys. Bird density and species richness varied with the structure of the vegetative communities present at the three sites. Avian species richness and total detections were higher in the three-zone buffer than in both the shrub and planted buffer, likely a result of the diversity of vegetation at the site. These data suggest that restoration of riparian areas by allowing fallow vegetation to recolonize is at the very least equally beneficial to avian wildlife as is restoration by planting specific grass, shrub, and tree species. Buffer restoration by natural revegetation using this method could be recommended as an alternative to implementation by planting riparian species due to its simplicity and cost effectiveness.}, number={2}, journal={SOUTHEASTERN NATURALIST}, author={Smith, Timothy A. and Osmond, Deanna L. and Moorman, Christopher E. and Stucky, Jon M. and Gilliam, J. Wendell}, year={2008}, pages={277–288} }
 @article{dell'olio_maguire_osmond_2008, title={Influence of Mehlich-3 extractable aluminum on phosphorus retention in organic soils}, volume={173}, ISSN={["1538-9243"]}, DOI={10.1097/ss.0b013e31815d8eb7}, abstractNote={Phosphorus (P) regulations in North Carolina (NC) assume that organic soils have little ability to retain P, and losses of P from these soils are of concern for the health of aquatic ecosystems. However, recent research has indicated decreased water-soluble P (WSP) in organic soils in the presence of high Al concentrations. Our objectives were to determine (i) the concentrations of organic matter (OM), and Mehlich-3 Al and Fe in deep and shallow organic soils in NC, and (ii) how these factors affect P retention. We sampled four organic soil series and determined Mehlich-3 P, Al, and Fe (M3P, M3Al, M3Fe), WSP, total P, pH, particle size distribution, and OM. Water-soluble P and M3P were also measured in a 21-day incubation study, in which P was added at a rate equivalent to 150 kg P ha−1. The main cation responsible for P retention was Al, and the mean topsoil M3Al concentrations (1926 mg kg−1) in these organic soils were close to three times higher than those observed in another study of mostly mineral NC soils. Mehlich-3 Fe was not significantly related to WSP. Retention of added P was negatively related to OM and positively related to M3Al. The ratio of OM and M3Al was the best predictor of WSP and retention of added P. The results from this study indicate that organic soils can retain P more strongly than previously thought, and their ability to retain P is best described by the ratio of OM and M3Al.}, number={2}, journal={SOIL SCIENCE}, author={Dell'Olio, Laura A. and Maguire, Rory O. and Osmond, Deanna L.}, year={2008}, month={Feb}, pages={119–129} }
 @article{cahill_johnson_osmond_hardy_2008, title={Response of corn and cotton to starter phosphorus on soils testing very high in phosphorus}, volume={100}, ISSN={["0002-1962"]}, DOI={10.2134/agronj2007.0202}, abstractNote={Phosphorus from agricultural lands poses a problem in water resources. In 2003, more than 48% of soil samples submitted to the North Carolina Department of Agriculture and Consumer Services (NCDA&CS) soil testing laboratory tested very high in soil P (>120 mg dm−3 P). As soil test P increases, off‐site P loss increases, through erosion, soluble P runoff, or leaching. On soils testing above high soil test P (60–120 mg dm−3 P), studies from the northeast and midwest United States demonstrate that no corn (Zea mays L.) or cotton (Gossypium spp.) yield response from additional fertilizer is expected. However, there have been limited studies on the effects of starter‐P fertilizer on soils with very high P status in North Carolina and the southeast. Therefore, we undertook a study in the three physiographic regions (coastal plain, piedmont, and mountains) of North Carolina to determine if the use of starter‐P fertilizer would affect the growth of corn and cotton on soils having very high soil test P. Treatments were starter N and P, and starter N only. Treatment differences were not observed for corn, while the N‐only treatment had greater tissue N than the N‐ and P‐starter treatment in Piedmont cotton. Additionally, the use of only starter‐N is typically more cost effective than using both N and P starter fertilizer. For production, environmental, and economic reasons, starter‐P fertilizer is not warranted on North Carolina fields with very high soil test P values.}, number={3}, journal={AGRONOMY JOURNAL}, author={Cahill, Sheri and Johnson, Amy and Osmond, Deanna and Hardy, David}, year={2008}, pages={537–542} }
 @article{israel_osmond_roberts_2007, title={Potential impacts of implementation of the phosphorus loss assessment tool (PLAT) on the poultry industry in North Carolina: Case studies}, volume={62}, number={1}, journal={Journal of Soil & Water Conservation}, author={Israel, D. W. and Osmond, D. L. and Roberts, J. C.}, year={2007}, pages={48–54} }
 @article{cahill_osmond_crozier_israel_weisz_2007, title={Winter wheat and maize response to urea ammonium nitrate and a new urea formaldehyde polymer fertilizer}, volume={99}, DOI={10.2134/agronj2OO7.0132}, number={6}, journal={Agronomy Journal}, author={Cahill, S. and Osmond, Deanna and Crozier, C. and Israel, D. and Weisz, R.}, year={2007}, pages={1645–1653} }
 @article{osmond_cabrera_feagley_hardee_mitchell_moore_mylavarapu_oldham_stevens_thom_et al._2006, title={Comparing ratings of the southern phosphorus indices}, volume={61}, number={6}, journal={Journal of Soil & Water Conservation}, author={Osmond, D. L. and Cabrera, M. L. and Feagley, S. E. and Hardee, G. E. and Mitchell, C. C. and Moore, P. A. and Mylavarapu, R. S. and Oldham, J. L. and Stevens, J. C. and Thom, W. C. and et al.}, year={2006}, pages={325–337} }
 @inproceedings{smeltz_evans_osmond_2006, title={Controlled Drainage and Nutrient Management Planning Reduce Drainage Outflow and Nitrogen Transport}, ISBN={9780784408568}, url={http://dx.doi.org/10.1061/40856(200)254}, DOI={10.1061/40856(200)254}, abstractNote={Controlled drainage, nutrient management planning, and a combination of both were implemented and evaluated throughout the upper Core Creek watershed to reduce nutrient loading to the Neuse River. Hydrology and drainage water quality were monitored at fifteen locations within the watershed for a period of five years. DRAINMOD-N was calibrated on a field-by-field basis to predict long-term hydrology and nitrate losses based on BMPs implemented and crops grown throughout the watershed. Predicted NO 3 -N reduction was most effectively accomplished when controlled drainage and a nitrogen management plan were used in conjunction with one another. If implemented separately, a nitrogen management plan was predicted to be more effective than controlled drainage alone. The cropping system also impacted the drainage rate and nitrate loss from the fields. Potentially, a 30% and 75% nitrate reduction can be achieved growing cotton or soybeans, respectively, as compared to corn. Controlled drainage reduced the drainage outflow by 6.8 centimeters (21.3%) annually, compared to conventional drainage. This flow reduction accounted for 11.5% of the NO 3 -N reduction leaving the watershed.}, booktitle={World Environmental and Water Resource Congress 2006}, publisher={American Society of Civil Engineers}, author={Smeltz, H. L. and Evans, R. O. and Osmond, D. L.}, year={2006}, month={May} }
 @article{smith_osmond_gilliam_2006, title={Riparian buffer width and nitrate removat in a tagoon-effluent irrigated agricutturat area}, volume={61}, number={5}, journal={Journal of Soil & Water Conservation}, author={Smith, T. A. and Osmond, D. L. and Gilliam, J. W.}, year={2006}, pages={273–281} }
 @article{hayes_mclaughlin_osmond_2005, title={Polyacrylamide use for erosion and turbidity control on construction sites}, volume={60}, number={4}, journal={Journal of Soil & Water Conservation}, author={Hayes, S. A. and McLaughlin, R. A. and Osmond, D. L.}, year={2005}, pages={193–199} }
 @article{johnson_osmond_hodges_2005, title={Predicted impact and evaluation of North Carolina's phosphorus indexing tool}, volume={34}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2005.0020}, abstractNote={ABSTRACTIncreased concern about potential losses of phosphorus (P) from agricultural fields receiving animal waste has resulted in the implementation of new state and federal regulations related to nutrient management. In response to strengthened nutrient management standards that require consideration of P, North Carolina has developed a site‐specific P indexing system called the Phosphorus Loss Assessment Tool (PLAT) to predict relative amounts of potential P loss from agricultural fields. The purpose of this study was to apply the PLAT index on farms throughout North Carolina in an attempt to predict the percentage and types of farms that will be forced to change management practices due to implementation of new regulations. Sites from all 100 counties were sampled, with the number of samples taken from each county depending on the proportion of the state's agricultural land that occurs in that county. Results showed that approximately 8% of producers in the state will be required to apply animal waste or inorganic fertilizer on a P rather than nitrogen basis, with the percentage increasing for farmers who apply animal waste (approximately 27%). The PLAT index predicted the greatest amounts of P loss from sites in the Coastal Plain region of North Carolina and from sites receiving poultry waste. Loss of dissolved P through surface runoff tended to be greater than other loss pathways and presents an area of concern as no best management practices (BMPs) currently exist for the reduction of in‐field dissolved P. The PLAT index predicted the areas in the state that are known to be disproportionately vulnerable to P loss due to histories of high P applications, high densities of animal units, or soil type and landscapes that are most susceptible to P loss.}, number={5}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Johnson, AM and Osmond, DL and Hodges, SC}, year={2005}, pages={1801–1810} }
 @article{osmond_hardy_2004, title={Characterization of turf practices in five North Carolina communities}, volume={33}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2004.0565}, abstractNote={Limited information exists on specific urban lawn care practices in the United States. We conducted a door-to-door lawn care survey in five North Carolina communities to determine suburban fertilizer, pesticide, and water use. These communities, Cary, Goldsboro, Kinston, New Bern, and Greenville, are mostly located within the Neuse River basin, a nutrient-sensitive water resource. Residents in Cary used lawn care companies more than twice as frequently as residents in the other communities (43 compared with 20%). Cary had the smallest mean lawn size (445 m2), while the largest was in Goldsboro (1899 m2). Tall fescue [Festuca arundinacea Schreb.] was the predominant grass type in Cary (99%), and centipedegrass [Eremochloa ophiuroides (Munro) Hack.] or centipedegrass mixtures were the predominant grass types in Greenville and New Bern. Kinston had the lowest fertilizer usage with only 54% of the residents using fertilizer; Cary had the highest rate of 83%. The average N fertilizer rate applied to the lawns was dissimilar ranging from 24 to 151 kg N ha−1 Analysis of variance results for fertilizer rates and household income indicated a significant difference (P < 0.05) in application rate between high- and medium-income levels and the low-income level. Cary, Goldsboro, and Greenville had approximately the same number of fertilizer applications per year (1.5), whereas the average number of fertilizer applications per year in New Bern was 3.0. Most household residents (53%) used instructions on the bag and either grass type and/or lawn area to guide them on fertilizer application rates.}, number={2}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Osmond, DL and Hardy, DH}, year={2004}, pages={565–575} }
 @article{wafer_richards_osmond_2004, title={Construction of platinum-tipped redox probes for determining soil redox potential}, volume={33}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2004.2375}, abstractNote={ABSTRACTRedox probes are typically constructed by soldering Pt wire to a metal wire or rod, such as copper or brass. The junction between the Pt and wire or rod is often sealed with an epoxy resin and hardener or with heat‐shrink tubing. Microcracks (small cracks invisible to the unaided eye) can form in the hardened resin and result in incorrect readings. The hardened resin is not easily removed, making repairs difficult. Heat‐shrink tubing is thin, lacks rigidity, and can be damaged in the soil. The method described in this paper used a thick‐walled, adhesive‐lined terminal insulator to seal the junction. The terminal insulators were easily applied and removed, which made faulty probes easy to repair. Two‐hundred forty probes were made with this method and eight were made with a marine epoxy resin. The probes were tested with a redox buffer solution (Light Solution) and were usable if they read +476 ± 10 mV. The probes were installed 0.76 and 1.5 m deep in the soil. The ability of the probes to provide reliable redox readings was examined by testing selected probes after 10 mo of use and testing all of the probes after completion of the study (19 mo). Ten of the twelve probes tested after 10 mo worked satisfactorily, while the other two clearly malfunctioned before testing. After the study was completed, 236 of the 240 of the probes worked satisfactorily. These results indicate that the construction method presented produces reliable, long‐lasting probes.}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Wafer, CC and Richards, JB and Osmond, DL}, year={2004}, pages={2375–2379} }
 @article{flowers_weisz_heiniger_osmond_crozier_2004, title={In-season optimization and site-specific nitrogen management for soft red winter wheat}, volume={96}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2004.0124}, abstractNote={application up to 70% without a reduction in grain yield compared to a grower’s practice. Site-specific N management based on an in-season assessment of Stone et al. (1996) used an on-the-go sensor measurcrop N status may offer producers increased grain yield, profitability, ing plant N spectral index to create submeter siteand spring N fertilizer use efficiency (SNUE). The goal of this study specific N management units based on an estimate of was to determine the distinct contributions of (i) in-season N rate optimization and (ii) site-specific N management. Our objective was in-season crop N status in wheat. This site-specific N to compare site-specific and field-specific N management with typical management system reduced N fertilizer by 32 and 57 growers’ practices to determine if site-specific N management (i) kg N ha 1 at two of three sites without a reduction in increased soft red winter wheat (Triticum aestivum L.) grain yield, grain yield compared with a typical grower’s practice. (ii) reduced N inputs, (iii) increased SNUE, and (iv) reduced withinThey also reported that the site-specific N application field grain yield variability. Research was conducted at eight sites in reduced spatial variation in wheat forage and grain yield 2000, 2001, and 2002. A randomized complete block design with two compared with the grower’s practice. or five N management systems was used at two and six sites, respecSimilarly, Raun et al. (2002) used a multispectral optitively. Site-specific management did not improve grain yield compared cal sensor to create 1-m2 site-specific N management with field-specific management when based on the same in-season units in wheat. A N fertilizer optimization algorithm estimation of optimum N rates. At sites where site-specific or field(NFOA) that estimates in-season crop N status and specific systems were compared with typical growers’ practices, grain potential grain yield was used to adjust N rates. They yield benefits of in-season N optimization (up to 2267 kg ha 1) were reported that by using NFOA, it might be possible to apparent. For grain yield, in-season optimization of N rate was more important than site-specific management. A large reduction in N inset more efficient and profitable fertilization levels and puts (up to 48.6%) was also attributed to in-season N rate optimizaincrease N use efficiency compared with typical growtion. After incorporating in-season optimization, a further reduction ers’ practices. in N inputs (up to 19.6%) was possible through site-specific applicaMulla et al. (1992), Bhatti et al. (1998), Stone et al. tion. Site-specific N application maximized SNUE compared with (1996), and Raun et al. (2002) compared site-specific N either field-specific or typical growers’ practices at all sites and reduced management based on either a preor in-season estiwithin-field grain yield variance at four sites. mate of the crop’s N requirement to a typical grower’s practice. Consequently, the reduction in N rates compared with growers’ practices might not have been the S N management is the adjusting of withinresult of site-specific application but could instead be field N fertilizer rates based on spatially variable due to using a preor in-season estimation of the crop’s factors that affect optimum N rate (Sawyer, 1994). This N requirement. practice may offer producers the ability to increase grain In the southeastern USA, Scharf and Alley (1993), yield, profitability, and N fertilizer efficiency by applyAlley et al. (1994), Weisz and Heiniger (2000), and ing N only where required for optimum plant growth. Weisz et al. (2001) developed a field-specific N manageSite-specific management may also be environmentally ment system for soft red winter wheat based on an inbeneficial to producers. season evaluation of the crop’s N requirement (Fig. 1). Mulla et al. (1992) created site-specific management This system first determines the whole-field tiller density units (18.3 m by 564–655 m) based on preseason soil N at Zadoks’ Growth Stage (GS) 25 (Zadoks et al., 1974). (nitrate N and ammonium N) tests and available soil When GS-25 tiller density is below a critical threshold water content. Similarly, Bhatti et al. (1998) created (540 tillers m 2), a GS-25 N application is made to insite-specific N management units based on crop produccrease tiller development (Ayoub, 1974; Power and tivity. In both cases, site-specific N reduced N fertilizer Alessi, 1978; Lutcher and Mahler, 1988; Scharf and Alley, 1993; Weisz et al., 2001). A GS-25 N application can stimulate tiller development in southeastern areas M. Flowers, USDA-ARS, Air Quality–Plant Growth and Dev. Res. because winter wheat does not enter a dormant state Unit, 3908 Inwood Rd., Raleigh, NC 27603; R. Weisz, Dep. of Crop in these southern latitudes. If GS-25 tiller density is Sci., North Carolina State Univ., Box 7620, Raleigh, NC 27695-7620; above the threshold, a GS-25 N application is not necesR. Heiniger, Dep. of Crop Sci, North Carolina State Univ., Vernon James Res. and Ext. Cent., 207 Research Rd., Plymouth, NC 27692; sary. At GS 30, a field-averaged tissue test is used to D. Osmond, Dep. of Soil Sci., North Carolina State Univ., Box 7619, optimize N application rates (Alley et al., 1994). This Raleigh, NC 27695-7619; and C. Crozier, Dep. of Soil Sci., North system resulted in an increase in estimated profit of $73 Carolina State Univ., Vernon James Res. and Ext. Cent., 207 Research ha 1 across 20 site-years (Scharf and Alley, 1993). Rd., Plymouth, NC 27692. Received 5 Dec. 2002. *Corresponding author (mike_flowers@ncsu.edu). While this system (Fig. 1) has been tested and adopted Published in Agron. J. 96:124–134 (2004).  American Society of Agronomy Abbreviations: GS, growth stage; SNUE, spring nitrogen fertilizer use efficiency. 677 S. Segoe Rd., Madison, WI 53711 USA}, number={1}, journal={AGRONOMY JOURNAL}, author={Flowers, M and Weisz, R and Heiniger, R and Osmond, D and Crozier, C}, year={2004}, pages={124–134} }
 @article{wossink_osmond_2002, title={Farm economics to support the design of cost-effective Best Management Practice (BMP) programs to improve water quality: Nitrogen control in the Neuse River Basin, North Carolina}, volume={57}, ISBN={0022-4561}, number={4}, journal={Journal of Soil & Water Conservation}, author={Wossink, G. A. A. and Osmond, D. L.}, year={2002}, pages={213} }
 @article{line_white_osmond_jennings_mojonnier_2002, title={Pollutant export from various land uses in the upper Neuse River Basin}, volume={74}, ISSN={["1061-4303"]}, DOI={10.2175/106143002X139794}, abstractNote={Because of the relatively high variability of pollutant export from urban land uses, a significant number of monitoring studies, including data from many storms, are needed to adequately characterize export from urban land uses. Pollutant runoff from six small drainage areas with different land uses was monitored for at least 20 storm events over the course of more than 1 year. The land uses included single‐family residential, golf course, industrial, dairy cow pasture, construction site, and wooded site. Average event mean concentrations and total annual load were computed for nitrogen forms, total phosphorus, and sediment from the land uses. Annual total nitrogen export was greatest for the construction land use during the house‐building phase, followed closely by the residential and golf course land uses. Total phosphorus export was greatest for the golf course site followed by the pasture and residential land uses. Sediment export was greatest for the construction site during the rough grading phase, which averaged more than 10 times more sediment export than any of the other sites. To estimate export from a multiuse urban watershed, total nitrogen, phosphorus, and sediment export from the residential, golf course, and construction sites were averaged. The average total nitrogen, phosphorus, and sediment export from the three land uses was, respectively, 269, 302, and 256% greater than the corresponding exports from the wooded site, which was considered similar to the predevelopment land use. Additionally, analyses of rainfall samples indicated that a considerable portion of the nitrogen export from these sites likely comes from nitrogen in rainfall.}, number={1}, journal={WATER ENVIRONMENT RESEARCH}, author={Line, DE and White, NM and Osmond, DL and Jennings, GD and Mojonnier, CB}, year={2002}, pages={100–108} }
 @article{osmond_ranells_hodges_hansard_xu_jones_pratt_2002, title={Tracking nitrogen loading reductions from agricultural sources: NLEW}, ISBN={1901502787}, journal={Climate variability and change : hydrological impacts}, publisher={Wallingford, Oxfordshire, UK : International Association of Hydrological Sciences}, author={Osmond, D. L. and Ranells, N. N. and Hodges, S. C. and Hansard, R. and Xu, L. and Jones, T. E. and Pratt, S. H.}, editor={Demuth, S. and Askew, A.Editors}, year={2002} }
 @article{osmond_platt_2000, title={Characterization of suburban nitrogen fertilizer and water use on residential turf in Cary, North Carolina}, volume={10}, number={2}, journal={HortTechnology}, author={Osmond, D. L. and Platt, J. L.}, year={2000}, pages={320} }
 @article{line_harman_jennings_thompson_osmond_2000, title={Nonpoint-source pollutant load reductions associated with livestock exclusion}, volume={29}, ISSN={["0047-2425"]}, DOI={10.2134/jeq2000.00472425002900060022x}, abstractNote={AbstractCattle (Bos taurus) grazing on unimproved pastures can be a significant, yet often overlooked, source of pollutants to surface waters, especially when the cattle have unlimited access to streams in the pastures. Livestock exclusion from streams has been demonstrated to reduce sediment and possibly nutrient yield from streams draining pastures. The purpose of this study was to evaluate the effects of excluding dairy cows from, and planting trees in, a 335‐m‐long and 10‐ to 16‐m‐ wide riparian corridor along a small North Carolina stream. Analysis of 81 wk of pre‐exclusion and 137 wk of post‐exclusion fencing data documented 33, 78, 76, and 82% reductions in weekly nitrate + nitrite, total Kjeldahl nitrogen (TKN), total phosphorus (TP), and sediment loads, respectively, from the 14.9‐ha pasture area adjacent to the fenced section of stream. Statistical analyses by t‐tests and analysis of variance suggested that the reductions in mean weekly loads post‐fencing were significant (P < 0.05) for all pollutants except nitrate + nitrite. Thus, the results indicated that livestock exclusion and subsequent riparian vegetation establishment was effective at reducing pollutant export from an intensively grazed pasture.}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Line, DE and Harman, WA and Jennings, GD and Thompson, EJ and Osmond, DL}, year={2000}, pages={1882–1890} }
 @misc{line_jennings_mclaughlin_osmond_harman_lombardo_tweedy_spooner_1999, title={Nonpoint sources}, volume={71}, ISSN={["1554-7531"]}, DOI={10.2175/106143099X133965}, abstractNote={Water Environment ResearchVolume 71, Issue 5 p. 1054-1069 Fate and Effect of PollutantFree Access Nonpoint Sources Daniel E. Line, Daniel E. LineSearch for more papers by this authorGregory D. Jennings, Gregory D. JenningsSearch for more papers by this authorRichard A. McLaughlin, Richard A. McLaughlinSearch for more papers by this authorDeanna L. Osmond, Deanna L. OsmondSearch for more papers by this authorWilliam A. Harman, William A. HarmanSearch for more papers by this authorLaura A. Lombardo, Laura A. LombardoSearch for more papers by this authorKevin L. Tweedy, Kevin L. TweedySearch for more papers by this authorJean Spooner, Jean SpoonerSearch for more papers by this author Daniel E. Line, Daniel E. LineSearch for more papers by this authorGregory D. Jennings, Gregory D. JenningsSearch for more papers by this authorRichard A. McLaughlin, Richard A. McLaughlinSearch for more papers by this authorDeanna L. Osmond, Deanna L. OsmondSearch for more papers by this authorWilliam A. Harman, William A. HarmanSearch for more papers by this authorLaura A. Lombardo, Laura A. LombardoSearch for more papers by this authorKevin L. Tweedy, Kevin L. TweedySearch for more papers by this authorJean Spooner, Jean SpoonerSearch for more papers by this author First published: 15 August 1999 https://doi.org/10.2175/106143099X133965Citations: 13AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume71, Issue51999 Literature ReviewAugust 1999Pages 1054-1069 RelatedInformation}, number={5}, journal={WATER ENVIRONMENT RESEARCH}, author={Line, DE and Jennings, GD and McLaughlin, RA and Osmond, DL and Harman, WA and Lombardo, LA and Tweedy, KL and Spooner, J}, year={1999}, month={Aug}, pages={1054–1069} }
 @misc{line_mclaughlin_osmond_jennings_harman_lombardo_spooner_1998, title={Nonpoint sources}, volume={70}, ISSN={["1554-7531"]}, DOI={10.2175/106143098X134514}, abstractNote={and Renormalized Perturbation Expansion. Adv. Water Res., 20,5. Zhang, R.D. (1997a) Determination of Soil Sorptivity and Hydraulic Conductivity from the Disk Infiltrometer. Soil Sci. Soc. Am. J., 61,4. Zhang, R.D. (I997b) Infiltration Models for the Disk Infiltrometer. Soil Sci. Soc. Am. J., 61, 6. Zhang, R.; Shouse, S.; and Yates, S. (1997) Use of Pseudo-Crossvariograms and Cokriging to Improve Estimates of Soil Solute Concentrations. Soil Sci. Soc. Am. J., 61, 5. Zhang, Y.K. (1997) On the Variances of 2nd Spatial Moments of a Nonergodic Plume in Heterogeneous Aquifers. Water Resour. Res., 33,8. Zhang, Y.M.; Maier, W.I.; and Miller, R.M. (1997) Effect of Rhamnolipids on the Dissolution, Bioavailability and Biodegradation of Phenanthrene. Environ. Sci. Technol., 31, 8. Zhao, L.T.; Gray, D.M.; and Male, D.H. (1997) Numerical Analysis of Simultaneous Heat and Mass Transfer during Infiltration into Frozen Ground. J. Hydrol., 200. Zhou, D.G., and Blunt, M. (1997) Effect of Spreading Coefficient on the Distribution of Light Nonaqueous Phase Liquid in the Subsurface. J. Contam. Hydro/., 25, I. Zhou, J.L.; Rowland, 5.1.; Mantoura, R.F.; and Lane, M.e. (1997) Desorption of Teftuthrin Insecticide from Soil in Simulated RainfallRunoff Systems-Kinetic-Studies and Modeling. Water Res. (G.B.), 31, 1.}, number={4}, journal={WATER ENVIRONMENT RESEARCH}, author={Line, DE and McLaughlin, RA and Osmond, DL and Jennings, GD and Harman, WA and Lombardo, LA and Spooner, J}, year={1998}, month={Jun}, pages={895–912} }
 @book{osmond_1997, title={1997 summary report: Section 319 National Monitoring Program projects}, publisher={Washington, D.C.: U.S. Environmental Protection Agency, Office of Water}, author={Osmond, D. L.}, year={1997} }
 @misc{line_osmond_coffey_mclaughlin_jennings_gale_spooner_1997, title={Nonpoint sources}, volume={69}, ISSN={["1554-7531"]}, DOI={10.2175/106143097X135055}, abstractNote={Micellar Solubilization of Polynuclear Aromatic Hydrocarbons in Coal Tar-Contaminated Soils. Environ. Sci. Technol., 30,2104. Yiacoumi, S., and Rao, A.V. (1996) Organic Solute Uptake from Aqueous Solutions by Soil: A New Diffusion Model. Water Resour. Res., 32, 431. Yonezawa, e.; Tanaka, T.; and Kamioka, H. (1996) Water-Rock Reactions During Gamma-Ray Irradiation. Appl. Geochem., 11, 461. Yoon, J.-H., and Shoemaker, e.A. (1996) Applications of SALQR and Evolutionary Algorithms to Optimization of Groundwater Bioremediation. Computat. Methods Water Resour. XI, Cancun, Mexico, Computational Mechanics Publications, Southampton, U.K., 1,383. You, e.N., and Liu, J.e. (1996) Desorptive Behavior of Chlorophenols in Contaminated Soils. Water Sci. Technol. (G.B.), 33, 263. You, G.R.; Sayles, G.D.; Kupferle, M.J.; Kim, I.S.; and Bishop, P.L. (1996) Anaerobic DDT Biotransformation: Enhancement by Application of Surfactants and Low Oxidation Reduction Potential. Chemosphere, 32, 2269. Yu, S.C.T. (1995) Transport and Fate of Chlorinated Hydrocarbons in the Vadose Zone-A Literature Review with Discussions on Regulatory Implications. J. Soil Contam., 4, 25. Yu, Y.S.; Bailey, G.W.; and Jin, X.C. (1996) Application of a Lumped, Nonlinear Kinetics Model to Metal Sorption on Humic Substances. 1. Environ. Qual., 25, 552. Zaidel, J.; Russo, D.; and Feldman, G. (1996) Theoretical Analysis of the Impact of Vapor Transport on the NAPL Distribution in Dry Soils. Adv. Water Resour., 19, 145. Zegeling, P.A. (1996) Numerical Solution of Advection-Dispersion Models Using Dynamically-Moving Adaptive Grids. Computat. Methods Water Resour. XI, Cancun, Mex., Computational Mechanics Publications, Southampton, U.K., 1, 593. Zhang, D., and Zhang, Y.-K. (1996) Higher-Order Velocity Covariance and Its Effect on Advective Transport in Three-Dimensional Heterogeneous Anisotropic Media. Computat. Methods Water Resour. Xl, Cancun, Mex., Computational Mechanics Publications, Southampton, U.K., 1, 689. Zhang, D.X., and Neuman, S.P. (1996a) Head and Velocity Covariances Under Quasi-Steady State Flow and Their Effects on Advective Transport. Water Resour. Res., 32,77.}, number={4}, journal={WATER ENVIRONMENT RESEARCH}, author={Line, DE and Osmond, DL and Coffey, SW and McLaughlin, RA and Jennings, GD and Gale, JA and Spooner, J}, year={1997}, month={Jun}, pages={844–860} }
 @book{osmond_line_spooner_1997, title={Section 319 National Monitoring Program: An overview}, publisher={Raleigh, N.C.: N.C. Cooperative Extension Service}, author={Osmond, D. L. and Line, D. E. and Spooner, J.}, year={1997} }
 @article{line_coffey_osmond_1997, title={WATERSHEDSS grass-AGNPS model tool}, volume={40}, DOI={10.13031/2013.21348}, abstractNote={A modeling tool that utilizes a raster-based geographic information system to build an input file for the 
spatially distributed pollutant runoff model, AGNPS, was developed as a component of the WATERSHEDSS decision 
support system. In addition to automatically computing input data from basic soils, topography, and land use maps, this 
modeling tool adds the capability to input point source, channel characteristic, and pesticide application data for userselected 
areas in the watershed. The tool was used to simulate runoff and sediment, nitrogen, and phosphorus loads for a 
small gaged watershed located in North Carolina. Output from the tool was compared to observed runoff and pollutant 
loads for 11 storms. Statistical comparisons between observed and model-simulated loads at two monitoring stations 
showed no significant difference between observed and predicted runoff volumes and nitrogen, phosphorus, and sediment 
loads, indicating that the modeling tool provides reasonable estimates of pollutant loads from storm events.}, number={4}, journal={Transactions of the ASAE}, author={Line, D. E. and Coffey, S. W. and Osmond, Deanna}, year={1997}, pages={971–975} }
 @article{osmond_gannon_gale_line_knott_phillips_turner_foster_lehning_coffey_et al._1997, title={WATERSHEDSS: A decision support system for watershed-scale nonpoint source water quality problems}, volume={33}, ISSN={["0043-1370"]}, DOI={10.1111/j.1752-1688.1997.tb03513.x}, abstractNote={ABSTRACT:  A significant portion of all pollutants entering surface waters (streams, lakes, estuaries, and wetlands) derives from non‐point source (NPS) pollution and, in particular, agricultural activities. The first step in restoring a water resource is to focus on the primary water quality problem in the watershed. The most appropriate NPS control measures, which include best management practices (BMPs) and landscape features, such as wetlands and riparian areas, can then be selected and positioned to minimize or mitigate the identified pollutant(s). A computer‐based decision sup. port and educational software system, WATERSHEDSS (WATER, Soil, and Hydro‐Environmental Decision Support System), has been developed to aid managers in defining their water quality problems and selecting appropriate NPS control measures. The three primary objectives of WATERSHEDSS are (1) to transfer water quality and land treatment information to watershed managers in order to assist them with appropriate land management/land treatment decisions; (2) to assess NPS pollution in a watershed based on user‐supplied information and decisions; and (3) to evaluate, through geographical information systems‐assisted modeling, the water quality effects of alternative land treatment scenarios. WATERSHEDSS is available on the World Wide Web (Web) at http://h2osparc.wq.ncsu.edu.}, number={2}, journal={JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION}, author={Osmond, DL and Gannon, RW and Gale, JA and Line, DE and Knott, CB and Phillips, KA and Turner, MH and Foster, MA and Lehning, DE and Coffey, SW and et al.}, year={1997}, month={Apr}, pages={327–341} }
 @article{osmond_riha_1996, title={Nitrogen fertilizer requirements for maize produced in the tropics: A comparison of three computer-based recommendation systems}, volume={50}, ISSN={["1873-2267"]}, DOI={10.1016/0308-521X(95)00009-T}, abstractNote={Nitrogen (N) is often the most limiting nutrient for tropically produced maize (Zea mays), yet in many tropical countries, N fertilizer field trials are beyond the institutional and financial capabilities of governments. Under such conditions, simple models to predict N fertilizer requirements can be useful tools. In this study, three methods of predicting N fertilizer requirements, the Stanford, the Transfer Coefficient, and the N Mass Balance models, were selected for evaluation. An expert system was developed to estimate model parameters from qualitative and quantitative information. Six published data sets, encompassing a range of tropical agro-ecological conditions, were used to validate model performance. For the majority of the data sets, the Stanford model predicted average N fertilizer requirements most accurately, whereas predictions made using the N Mass Balance model and the Transfer Coefficient models were less accurate.}, number={1}, journal={AGRICULTURAL SYSTEMS}, author={Osmond, DL and Riha, SJ}, year={1996}, pages={37–50} }
 @article{osmond_wilson_raper_1982, title={FATTY-ACID COMPOSITION AND NITRATE UPTAKE OF SOYBEAN ROOTS DURING ACCLIMATION TO LOW-TEMPERATURE}, volume={70}, ISSN={["0032-0889"]}, DOI={10.1104/pp.70.6.1689}, abstractNote={Fatty acid composition of old and new roots was determined for soybeans (Glycine max [L.] Merr. cv Ransom) at root-zone temperatures of 14, 18, and 22 degrees C during a 26-day period. New roots had a greater concentration of polyunsaturated fatty acids than old roots. The ratio of polyunsaturated to saturated fatty acid concentration in new roots exposed to 14 and 18 degrees C peaked at 16 days and declined, while the corresponding ratio in old roots increased throughout the treatment period. Apparently the response of fatty acid composition in old and new roots to low temperature was mediated by tissue aging or differentiation. These findings were contrary to the concept that modifications in fatty acid composition remain constant at lower temperatures.The function of root tissues exposed to lower temperature was evaluated with respect to the ability of the root systems to absorb NO(3) (-). Over the relatively long periods of exposure, the ability of whole root systems to absorb NO(3) (-) was similar at cool and warm temperatures. The effect of cool temperature on functioning of roots appeared to involve reductions in the rates of initiation and differentiation of young root tissues rather than changes in membrane permeability related to alteration of fatty acid composition.}, number={6}, journal={PLANT PHYSIOLOGY}, author={OSMOND, DL and WILSON, RF and RAPER, CD}, year={1982}, pages={1689–1693} }