@article{campbell_seepaul_iboyi_anderson_baldwin_bennett_crozier_george_hagan_lee_et al._2023, title={Agronomic performance and the effect of genotype-by-environment interaction for Brassica carinata in the southeastern US}, volume={203}, ISSN={["1872-633X"]}, DOI={10.1016/j.indcrop.2023.117196}, abstractNote={Carinata (Brassica carinata A. Braun) is an emerging oilseed crop with potential as a dual use winter cover/cash crop in the southeastern US region. Although carinata is historically cultivated as a spring crop in northern latitudes, incorporating carinata into southeastern US cropping systems can provide winter/cover ecosystem services and a bio-feedstock for a high value, renewable aviation fuel without displacing feed and food crops. In this study, our major objective was to quantify the agronomic performance and stability of selected carinata genotypes across several locations in the southeastern US. Extensive field evaluations of twelve, elite carinata genotypes, arranged in a randomized complete block design with four replications, were conducted from 2016 to 2019 across Mississippi, Alabama, Georgia, Florida, South Carolina, and North Carolina. Data was collected on days to 50% bolting, days to 50% flowering, plant height, grain yield, and test weight. Results demonstrated the ability to produce viable grain yields across the region, but also highlighted the impact of freezing temperatures on winter production. In total 20% of all environments were lost to mortality due to freezing temperatures. Overall, genotype 15 produced the highest grain yield across individual environments, topping the trial in 74% of all environments. However, both crossover and non-crossover genotype × environment interactions were detected for agronomic traits, with problematic crossover interactions more prevalent for days to 50% bolting and days to 50% flowering. Our results also suggest the southeastern US be separated into three mega environments to include 1) northern Georgia, South Carolina, and North Carolina, 2) southern and central Georgia and Alabama, and 3) northern Florida. Future efforts to identify advanced breeding lines and/or commercial seed products with adaptation to the region should consider field testing in each of these mega environments.}, journal={INDUSTRIAL CROPS AND PRODUCTS}, author={Campbell, B. Todd and Seepaul, Ramdeo and Iboyi, Joseph E. and Anderson, William F. and Baldwin, Brian S. and Bennett, Rick and Crozier, Carl R. and George, Sheeja and Hagan, Austin K. and Lee, Dewey and et al.}, year={2023}, month={Nov} }
 @article{bashyal_mulvaney_crozier_iboyi_perondi_post_iskandar_leon_landry_wilson_et al._2023, title={Brassica carinata nutrient accumulation and partitioning across maturity types and latitude}, volume={2}, ISSN={["1435-0653"]}, url={https://doi.org/10.1002/csc2.20900}, DOI={10.1002/csc2.20900}, abstractNote={Abstract}, journal={CROP SCIENCE}, author={Bashyal, Mahesh and Mulvaney, Michael J. and Crozier, Carl R. and Iboyi, Joseph E. and Perondi, Daniel and Post, Angela and Iskandar, Keola and Leon, Ramon G. and Landry, Gabriel M. and Wilson, Chris and et al.}, year={2023}, month={Feb} }
 @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={Abstract}, 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{carvalho_howard_amoozegar_crozier_johnson_heitman_2023, title={Water vapor transport through bioenergy grass residues and its effects on soil water evaporation}, volume={10}, ISSN={["1539-1663"]}, url={https://doi.org/10.1002/vzj2.20282}, DOI={10.1002/vzj2.20282}, abstractNote={Abstract}, journal={VADOSE ZONE JOURNAL}, author={Carvalho, Henrique D. R. and Howard, Adam M. and Amoozegar, Aziz and Crozier, Carl R. and Johnson, Amy M. and Heitman, Joshua L.}, year={2023}, month={Oct} }
 @article{tilley_jordan_heiniger_vann_crozier_gatiboni_2021, title={A survey of twin-row cropping systems in North Carolina}, volume={7}, ISSN={["2374-3832"]}, DOI={10.1002/cft2.20099}, abstractNote={Abstract}, number={1}, journal={CROP FORAGE & TURFGRASS MANAGEMENT}, author={Tilley, M. Scott and Jordan, David L. and Heiniger, Ronnie W. and Vann, Rachel and Crozier, Carl R. and Gatiboni, Luke}, year={2021} }
 @article{crozier_carvalho_johnson_chinn_heitman_2021, title={Appropriate "marginal" farmlands for second-generation biofuel crops in North Carolina}, volume={6}, ISSN={["2471-9625"]}, DOI={10.1002/ael2.20041}, abstractNote={Abstract}, number={1}, journal={AGRICULTURAL & ENVIRONMENTAL LETTERS}, author={Crozier, C. R. and Carvalho, H. D. R. and Johnson, A. and Chinn, M. and Heitman, J. L.}, year={2021} }
 @article{cockson_veazie_davis_barajas_post_crozier_leon_patterson_whipker_2021, title={The Impacts of Micronutrient Fertility on the Mineral Uptake and Growth of Brassica carinata}, volume={11}, ISBN={2077-0472}, url={https://doi.org/10.3390/agriculture11030221}, DOI={10.3390/agriculture11030221}, abstractNote={Many abiotic factors impact the yield and growth of Brassica carinata (commonly referred to as carinata or Ethiopian mustard). Very little is known about carinata and how mineral nutrients impact its growth, and more specifically, the sufficiency values for fertility over the plant’s growth cycle and life stages. This study explored the impacts that plant nutrients, specifically micronutrients, can have on the growth and development of carinata over its distinct life stages (rosette, bolting, flowering, and pod set). Plants were grown under varying micronutrient concentrations (0, 25, 50, 75, 87.5, and 100%) of a modified Hoagland’s solution. Data were collected on plant height, canopy diameter, leaf tissue mineral nutrient concentrations, and biomass. The results demonstrated that micronutrient fertility has profound impacts on the production of Brassica carinata during different life stages. Boron (B) exclusion had the greatest impact on the growth and reproduction of Brassica carinata, with the death of the apical meristem that resulted in a lack of siliques or seeds at the lowest rate. Optimal relative elemental leaf tissue concentrations varied among micronutrient fertility concentrations and life stages. Certain elements exhibited linear increases in nutrient leaf tissue accumulation as solution concentration increased without reaching a maximum concentration during specific life stages. Other life stages and/or elements produced distinct plateau leaf tissue mineral concentrations despite increasing fertility treatment concentrations such as B in the rosette stage (47.2–50.0 mg·kg−1), copper (Cu) (bolting stage at 6.62–7.57 mg·kg−1), zinc (Zn) (bolting stage at 27.47–39.87 and flowering at 33.98–43.50 mg·kg−1), molybdenum (Mo) (flowering stage at 2.42–3.23 mg·kg−1), and manganese (Mn) (bolting stage at 117.03–161.63 mg·kg−1). This work demonstrates that Brassica carinata has different fertility demands and will accumulate differing leaf tissue concentrations during its life stages. This work serves as a baseline for further uptake and portioning work for Brassica carinata.}, number={3}, journal={AGRICULTURE-BASEL}, publisher={MDPI AG}, author={Cockson, Paul and Veazie, Patrick and Davis, Matthew and Barajas, Gabby and Post, Angela and Crozier, Carl R. and Leon, Ramon G. and Patterson, Robert and Whipker, Brian E.}, year={2021}, month={Mar}, pages={221} }
 @article{stephenson_carvalho_castillo_crozier_smyth_heitman_2021, title={Water use and biomass yield of bioenergy crops in the North Carolina Piedmont}, volume={113}, ISSN={["1435-0645"]}, DOI={10.1002/agj2.20646}, abstractNote={Abstract}, number={3}, journal={AGRONOMY JOURNAL}, author={Stephenson, Thomas D. and Carvalho, Henrique D. R. and Castillo, Miguel S. and Crozier, Carl R. and Smyth, Thomas J. and Heitman, Joshua L.}, year={2021}, month={May}, pages={2463–2473} }
 @article{tilley_heiniger_crozier_2019, title={Tiller Initiation and its Effects on Yield and Yield Components in Winter Wheat}, volume={111}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2018.07.0469}, abstractNote={Core Ideas
A marking technique was used to monitor leaf and tiller development.
The earlier a tiller is formed the more kernels it produces.
Seeding rate influences tiller initiation and productivity.
}, number={3}, journal={AGRONOMY JOURNAL}, author={Tilley, M. Scott and Heiniger, Ronnie W. and Crozier, Carl R.}, year={2019}, pages={1323–1332} }
 @article{poole_skaggs_youssef_chescheir_crozier_2018, title={EFFECT OF DRAINAGE WATER MANAGEMENT ON NITRATE NITROGEN LOSS TO TILE DRAINS IN NORTH CAROLINA}, volume={61}, ISSN={["2151-0040"]}, DOI={10.13031/trans.12296}, abstractNote={Abstract.}, number={1}, journal={TRANSACTIONS OF THE ASABE}, author={Poole, C. A. and Skaggs, R. W. and Youssef, M. A. and Chescheir, G. M. and Crozier, C. R.}, year={2018}, pages={233–244} }
 @article{vann_reberg-horton_crozier_place_2018, title={Effect of Soybean Maturity, Crimson Clover Seeding Method, and Seeding Rate on Clover Biomass and Nitrogen Content}, volume={110}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2018.02.0118}, abstractNote={Core Ideas
Crimson clover seeding following the last cultivation of soybeans in July into MG3 to MG5 soybeans did not result in any substantial crimson clover growth in both years.
After harvest seeding into MG3 and MG4 soybean and aerial seeding into MG4 and MG5, soybean produced substantial clover N content ranging from 76 to 107 kg ha−1.
After harvest seeding behind MG5 soybeans reduced clover N content because late cover crop establishment restricted biomass production.
Seeding rate had no effect on clover biomass, clover N content, or corn yield for both drilled and aerially‐seeded crimson clover.
}, number={5}, journal={AGRONOMY JOURNAL}, author={Vann, R. A. and Reberg-Horton, S. C. and Crozier, C. R. and Place, G. T.}, year={2018}, pages={1829–1835} }
 @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} }
 @article{heitman_castillo_smyth_crozier_2018, title={Stem, Leaf, and Panicle Yield and Nutrient Content of Biomass and Sweet Sorghum}, volume={110}, ISSN={["1435-0645"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85052711959&partnerID=MN8TOARS}, DOI={10.2134/agronj2018.03.0178}, abstractNote={Core Ideas
Sorghum is a potential dedicated bioenergy crop both from biomass and sugar yields.
Increasing rates of N fertilizer affected biomass yield and nutrient removal for sorghum cultivar ES5200 by partitioning resources primarily toward the stem component.
For sorghum M81‐E, the seed head component accounted for a greater proportion of biomass, compared with sorghum ES5200, and biomass yield and nutrients were more evenly distributed among the three components.
Returning the leaf and seed head components back to the field to enhance soil fertility has the potential to provide at least 45, 7, and, 26 kg ha−1 of N, P, and K, respectively.
}, number={5}, journal={AGRONOMY JOURNAL}, author={Heitman, A. J. and Castillo, M. S. and Smyth, T. J. and Crozier, C. R.}, year={2018}, pages={1659–1665} }
 @article{wang_jot smyth_crozier_gehl_heitman_2018, title={Yield and Nitrogen Removal of Bioenergy Grasses as Influenced by Nitrogen Rate and Harvest Management in the Coastal Plain Region of North Carolina}, volume={11}, ISSN={1939-1234 1939-1242}, url={http://dx.doi.org/10.1007/S12155-017-9876-X}, DOI={10.1007/S12155-017-9876-X}, number={1}, journal={BioEnergy Research}, publisher={Springer Science and Business Media LLC}, author={Wang, Zan and Jot Smyth, T. and Crozier, Carl R. and Gehl, Ronald J. and Heitman, Adam J.}, year={2018}, month={Mar}, pages={44–53} }
 @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.
}, 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{wang_heitman_smyth_crozier_franzluebbers_lee_gehl_2017, title={Soil Responses to Bioenergy Crop Production in the North Carolina Piedmont}, volume={109}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2017.02.0068}, abstractNote={Core Ideas
Three bioenergy and two traditional cropping systems were compared in the North Carolina Piedmont.
Bioenergy crops sorghum, switchgrass, and giant mischanthus produced large yields.
Removal of N, P, and K was least for perennial bioenergy crops.
Perennial bioenergy crops had slightly poorer soil physical conditions after 3 yr.
Organic C pools were greatest with giant miscanthus and fescue.
}, number={4}, journal={AGRONOMY JOURNAL}, author={Wang, Zan and Heitman, Joshua L. and Smyth, T. Jot and Crozier, Carl R. and Franzluebbers, Alan and Lee, Sage and Gehl, Ronald J.}, year={2017}, pages={1368–1378} }
 @article{wang_smyth_crozier_gehl_heitman_2017, title={Yield and Nutrient Removal by Bioenergy Grasses on Swine Effluent Spray Fields in the Coastal Plain Region of North Carolina}, volume={10}, ISSN={1939-1234 1939-1242}, url={http://dx.doi.org/10.1007/S12155-017-9856-1}, DOI={10.1007/S12155-017-9856-1}, number={4}, journal={BioEnergy Research}, publisher={Springer Nature}, author={Wang, Zan and Smyth, T. Jot and Crozier, Carl R. and Gehl, Ronald J. and Heitman, Adam J.}, year={2017}, month={Jul}, pages={979–991} }
 @article{hesterberg_polizzotto_crozier_austin_2016, title={Assessment of trace element impacts on agricultural use of water from the Dan River following the Eden coal ash release}, volume={12}, ISSN={["1551-3793"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84941010545&partnerID=MN8TOARS}, DOI={10.1002/ieam.1669}, abstractNote={ABSTRACT}, number={2}, journal={INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT}, author={Hesterberg, Dean and Polizzotto, Matthew L. and Crozier, Carl and Austin, Robert E.}, year={2016}, month={Apr}, pages={353–363} }
 @article{savala_crozier_smyth_2016, title={Poultry Manure Nitrogen Availability Influences Winter Wheat Yield and Yield Components}, volume={108}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2015.0355}, abstractNote={Standard poultry manure use recommendations in North Carolina consider waste analysis but not differences among manure types, cropping seasons, or application timing. This study evaluated poultry manure source, N rate strategy, and application time effects on soft red winter wheat (Triticum aestivum L.) tiller density, yield components, grain yield, and N availability coefficients. Coefficients included fertilizer N equivalence based on grain yield and plant‐available N based on aboveground plant N content. Four field experiments used broiler litter (BL) and composted layer manure (CLM), two rates (67 and 134 kg total‐N ha−1), and three different application times (incorporated in October preplant, Feekes’ 3 in December/January, or Feekes’ 4 in February). Dual‐source treatments received 67 kg N ha−1 of manure plus 67 kg N ha−1 as urea ammonium nitrate (UAN) solution at Feekes’ 5. Fertilizer‐N (UAN) rate treatments (0, 39, 78, 117, and 156 kg N ha−1) were also included. Yields responded to N inputs but were lowest when BL and CLM were applied at 67 kg N ha−1 either preplant or at Feekes’ 3. Grain yield and N availability were greater with CLM than with BL (3.0 vs. 2.8 t ha−1 grain and 58 vs. 52 kg ha−1 N uptake, respectively). Availability coefficients ranged from 12 to 32%, lower than the standard assumed values of 50 to 60%. The feasible poultry manure application window includes preplant until Feekes’ 4, but fertilizing winter wheat crops solely with poultry manure may supply less N than intended.}, number={2}, journal={AGRONOMY JOURNAL}, author={Savala, Canon E. N. and Crozier, Carl R. and Smyth, T. Jot}, year={2016}, pages={864–872} }
 @article{crozier_gehl_hardy_heiniger_2014, title={Nitrogen Management for High Population Corn Production in Wide and Narrow Rows}, volume={106}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2013.0280}, abstractNote={Recent trends of planting corn (Zea mays L.) at higher populations and in narrower rows could influence optimum N management. This study investigates the effects of N rates (0–224 kg ha–1 N plus a low rate of uniformly applied starter) and timing (at planting, V5–V7 sidedress) on corn in wide and narrow rows (76–102 cm vs. 38–51 cm) at 13 sites over 3 yr in North Carolina. Early season N uptake, grain yield, and yield components were measured. Delaying N until sidedress increased yields, but there was an interaction effect with row spacing. Yields were greater with narrow rows and sidedress N (11.7 Mg ha–1) than with narrow rows and all N at planting (11.0 Mg ha–1) or with wide rows fertilized at either time (11.0 Mg ha–1), when averaged across N rates. Three ear yield components increased in response to N fertilization, leading to a 35% yield increase. Rows per ear increased from 15.5 to 15.9 ear–1, kernels per row increased from 27 to 32 row–1, and individual kernel mass increased from 226 to 253 mg. Aboveground plant N uptake by the V5 to V7 growth stage was only 9 kg ha–1, with very little additional N uptake in response to higher N rates. Sidedress N application at V5 to V7 maximized the formation of the ear yield components and grain yield for high population corn in narrow rows, but N timing did not affect yield or ear yield components of wide‐row corn.}, number={1}, journal={AGRONOMY JOURNAL}, author={Crozier, Carl R. and Gehl, Ronald J. and Hardy, David H. and Heiniger, Ronnie W.}, year={2014}, pages={66–72} }
 @article{parr_grossman_reberg-horton_brinton_crozier_2014, title={Roller-Crimper Termination for Legume Cover Crops in North Carolina: Impacts on Nutrient Availability to a Succeeding Corn Crop}, volume={45}, ISSN={["1532-2416"]}, DOI={10.1080/00103624.2013.867061}, abstractNote={Nitrogen (N) release from roll-killed legume cover crops was determined for hairy vetch (Vicia villosa Roth), crimson clover (Trifolium incarnatum L.), and a hairy vetch + rye (Secale cereale L.) biculture in an organic corn production system in North Carolina, USA. Cover crops were planted at two locations in fall 2008 and 2009, roll-killed in May, and no-till planted with corn (Zea mays L.). Inorganic soil N and mineral N flux were determined using potassium chloride (KCl) extractions and ion-exchange resin (Plant Root Simulator, PRS) probes at 2-week intervals for 12 weeks and compared to fertilized controls of 0 and 168 kg N ha−1. In 2009, greater plant available N under hairy vetch than under either 0 N control or crimson clover was found, with peak soil N occurring between 4 and 6 weeks after roll kill. Available soil N under crimson clover mulches was less than or equal to 0 N, suggesting net immobilization.}, number={8}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, publisher={Informa UK Limited}, author={Parr, Mary and Grossman, Julie M. and Reberg-Horton, S. Chris and Brinton, Carrie and Crozier, Carl}, year={2014}, month={Apr}, pages={1106–1119} }
 @article{poole_skaggs_cheschier_youssef_crozier_2013, title={Effects of drainage water management on crop yields in North Carolina}, volume={68}, ISSN={["1941-3300"]}, DOI={10.2489/jswc.68.6.429}, abstractNote={Research studies on a wide range of soils, crops, locations, and climates have shown that drainage water management (DWM), or controlled drainage (CD), can be used to substantially reduce the loss of nitrogen (N), and in some cases, phosphorus (P) from drained agricultural lands to surface waters. The adoption and widespread application of DWM depends on a variety of factors including its impact on crop yields. This paper presents results from a long term field study on the effect of DWM or CD on crop yields in a three-crop, two-year corn/wheat–soybean rotation. Yields were measured on replicated field scale plots under CD and conventional or free drainage (FD) treatments for a total of 18 crops on two experimental sites during the period from 1990 to 2011. Data were collected on 7 corn (Zea mays L.) crops, 5 wheat (Triticum aestivum L.) crops, and 6 soybean (Glycine max L.) crops. Controlled drainage had no significant effect on yields of winter wheat, which in North Carolina is grown in the wettest, coolest part of the year. Controlled drainage increased corn yields compared to FD in all seven years. The average yield increase for corn was 11%. Controlled drainage also increased soybean yield in all years with an average increase of 10% compared to FD. Such yield responses will promote the application of DWM, which will result in both economic and environmental benefits.}, number={6}, journal={JOURNAL OF SOIL AND WATER CONSERVATION}, author={Poole, C. A. and Skaggs, R. W. and Cheschier, G. M. and Youssef, M. A. and Crozier, C. R.}, year={2013}, pages={429–437} }
 @article{parr_grossman_reberg-horton_brinton_crozier_2011, title={Nitrogen Delivery from Legume Cover Crops in No-Till Organic Corn Production}, volume={103}, ISSN={["0002-1962"]}, DOI={10.2134/agronj2011.0007}, abstractNote={Sixteen winter annual cover crop cultivars were grown in North Carolina to determine total N accumulation, biological N fixation (BNF) potential, and compatibility with a roller‐crimper‐terminated organic corn (Zea maysL.) production system. Cover crops and termination dates were tested in a stripped block design. Treatments included hairy vetch (Vicia villosaRoth), common vetch (Vicia sativaL.), crimson clover (Trifolium incarnatumL.), Austrian winter pea (Pisum sativumL.), berseem clover (Trifolium alexandrinumL.), subterranean clover (Trifolium subterraneumL.), narrow leaf lupin (Lupinus angustifoliusL.), and Balansa clover (Trifolium michelianumSavi.), as well as bicultures of rye (Secale cerealeL.), hairy vetch, and Austrian winter pea. Roller‐crimper termination occurred in mid‐April, early May, and mid‐May. Total biomass, N concentration, and C/N ratios were determined for cover crops at all roll times and natural15N abundance at the optimal kill date. Hairy vetch and crimson clover monocultures had the greatest overall biomass in 2009, and bicultures the greatest biomass in 2010. Crimson clover successfully terminated in late April, hairy vetch and Austrian winter pea in mid‐May, and berseem clover and common vetch in late May. All cover crops except lupin and subterranean clover derived between 70 and 100% of their N from the atmosphere. Corn response to cover crop mulches was significantly affected by the time of rolling, with poor stands resulting from competition with insufficiently terminated mulches. Crimson, Balansa, and subterranean clover mulches resulted in poor corn yields despite relatively high levels of total N. The highest corn yields were achieved in hairy vetch and rye plus hairy vetch bicultures.}, number={6}, journal={AGRONOMY JOURNAL}, publisher={American Society of Agronomy}, author={Parr, M. and Grossman, J. M. and Reberg-Horton, S. C. and Brinton, C. and Crozier, C.}, year={2011}, pages={1578–1590} }
 @article{wall_weisz_crozier_heiniger_white_2010, title={Variability of the Illinois Soil Nitrogen Test across Time and Sampling Depth}, volume={74}, ISSN={["1435-0661"]}, DOI={10.2136/sssaj2009.0253}, abstractNote={There is potential for using the Illinois soil nitrogen test (ISNT) to improve N fertilizer recommendations for crops in the southeastern United States. The ISNT has been previously calibrated to predict N rates for corn (Zea mays L.) in North Carolina. This study evaluated the effects of sampling time, sampling depth, crop rotation, and fertilizer application on soil ISNT‐N during a 2‐yr period in the humid Coastal Plain and Piedmont regions of North Carolina. Ten sites were repeatedly sampled at 0‐ to 10‐, 10‐ to 20‐, and 20‐ to 30‐cm depths in fall, mid‐winter, and spring between October 2006 and May 2007. Illinois soil nitrogen test N, KCl‐extractable soil NO3–N and NH4–N, and soil organic matter (SOM) derived by loss‐on‐ignition (LOI) were evaluated at each sampling. Temporal changes in these soil parameters were evaluated for various crop rotations and N fertilizer applications. Soil ISNT‐N decreased with depth and showed significant variation with time at all three depths at all sites. Soil ISNT‐N was influenced by crop rotation and tillage but was not significantly affected by N fertilizer applications. Considering all sites together, ISNT‐N was well correlated with LOI; however, ISNT‐N was not correlated with LOI across time within sites. This suggests that the ISNT measured a fraction of SOM that behaved somewhat independently with time.}, number={6}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, publisher={Soil Science Society of America}, author={Wall, David P. and Weisz, Randy and Crozier, Carl R. and Heiniger, Ronnie W. and White, Jeffrey G.}, year={2010}, pages={2089–2100} }
 @article{crozier_havlin_hoyt_rideout_mcdaniel_2009, title={Three Experimental Systems to Evaluate Phosphorus Supply from Enhanced Granulated Manure Ash}, volume={101}, ISSN={["0002-1962"]}, DOI={10.2134/agronj2008.0187x}, abstractNote={Three experimental systems were used to evaluate a new P fertilizer since residual P levels at typical farm sites may make response detection unlikely. The systems were (i) greenhouse with low P soil, (ii) long‐term research sites with preexisting soil P gradients, and (iii) agricultural fields with prior P fertilization based on agronomic recommendations. The new fertilizer (animal waste by‐product, AWP: 5% N, 28% P2O5, 4% K2O, and 1% S) is an enhanced granulated manure ash. Corn (Zea mays L.), wheat (Triticum aestivum L.), and soybean [Glycine max (L.) Merr.] growth, P uptake, and residual soil Mehlich‐3 P were measured with agronomic rates of AWP or triple superphosphate (TSP). Greenhouse corn and wheat P uptake, and soil Mehlich‐3 P increased similarly with either fertilizer at rates equivalent to 0, 10, 20, 40, and 80 kg P ha−1. In long‐term research sites, grain yield increased with P fertilization in 8 of 12 tests, and was greater with TSP than with AWP in 3 of 12 tests. Plant P uptake increased in all 12 tests, and was greater with TSP in 1 of 12 tests. In previously fertilized agricultural fields, soil Mehlich‐3 P, but not yield, increased due to P fertilization. Fertilizer source differences were infrequent and relatively minor, but possibly due to lower water soluble P content of the AWP (70% versus 78% for TSP). Evaluation of such products requires an appropriate experimental system with low P soils that may be difficult to find on typical North Carolina farms.}, number={4}, journal={AGRONOMY JOURNAL}, author={Crozier, C. R. and Havlin, J. L. and Hoyt, G. D. and Rideout, J. W. and McDaniel, R.}, year={2009}, pages={880–888} }
 @article{holness_reddy_crozier_niedziela_2008, title={Evaluating inorganic nitrogen and rye-crimson clover mixture fertilization of spring broccoli and lettuce by (15)Nitrogen tracing and mass balance}, volume={31}, ISSN={["1532-4087"]}, DOI={10.1080/01904160802097359}, abstractNote={ABSTRACT Broccoli (Brassica oleraceaL. var. italica) and lettuce (Latuca sativaL.) were grown under greenhouse conditions with nitrogen (N) from a cover crop mixture of rye (Secale cerealeL.) and crimson clover (Trifolium incarnatumL.) and ammonium nitrate (NH4NO3). Individual cover crop species were produced with non-enriched or enriched (5 atom % NH4 15NO3) Hoagland Nutrient Solutions resulting in enriched rye [0.799% atom % 15N, 24:1 carbon (C):N ratio] and enriched clover (0.686% atom % 15N, 19:1 C:N ratio). Cover crops were applied as an equal mixture of rye and clover at 1884, 3768, and 5652 kg·ha− 1 dry weight to supply 26, 52, and 78 kg·ha− 1 N. Enriched materials were only applied at the 3768 kg·ha− 1 rate, either as enriched rye plus non-enriched clover or non-enriched rye plus enriched clover. Additional treatments consisted of an unfertilized control and three NH4NO3 fertilizer rates; 112, 224, and 336 kg·ha− 1 N for broccoli and 70, 140, and 210 kg·ha− 1 N for lettuce. Combination treatments were the standard cover crop rate (3768 kg·ha− 1) plus the lowest N fertilizer rate for each vegetable. Cover crops did not increase yield of either broccoli or lettuce, and contributed only 17% of the N in broccoli and 15% of the N in lettuce. The majority of cover crop 15N remained in the soil: 54.8% and 81.3% of rye and clover N, respectively, after broccoli harvest; and 68.1% and 79.2% of rye and clover N, respectively, after lettuce harvest. Broccoli plant tissue recoveries were 8.0% of the rye and 11.0 % of the clover 15N; while lettuce plant tissue recoveries were 6.3% (rye) and 4.1% (clover). Broccoli yield could not be assessed due to lack of floret development, but dry matter accumulation was maximized at 224 kg·ha− 1N. Lettuce yield and fertilizer N recovery efficiency (by mass balance) was maximized at 140 g·ha− 1 N.}, number={6}, journal={JOURNAL OF PLANT NUTRITION}, author={Holness, Rickie L. and Reddy, Muchha R. and Crozier, Carl R. and Niedziela, Carl E., Jr.}, year={2008}, pages={1033–1045} }
 @article{williams_crozier_white_sripada_crouse_2007, title={Comparison of soil nitrogen tests for corn fertilizer recommendations in the humid southeastern USA}, volume={71}, ISSN={["0361-5995"]}, DOI={10.2136/sssaj2006.0057}, abstractNote={Environmental concerns about increasing NO3 levels in watersheds in North Carolina and elsewhere indicate the need for better N fertilizer management. Nitrate levels might be reduced if N rates could be adjusted based on field‐ or site‐specific knowledge of corn (Zea mays L.) response to N fertilization. Currently, there is no effective soil N test for the humid southeastern USA. This study was conducted to compare three soil N tests for practicality, precision, and ability to correlate with economic optimum N rate (EONR) and fertilizer response on southeastern U.S. soils. The soil N tests were the Illinois soil N test (ISNT), the gas pressure test (GPT), and the incubation and residual N test (IRNT). Soil samples were collected from the sites of 16 N‐response trials from 2001 to 2003 where different mineralizable and residual N levels were expected. The ISNT was determined to be the most practical test because it was the easiest to perform and could be completed in 1 d. The ISNT and GPT had better precision (lower CV) than the IRNT (9 and 13 vs. 61%, respectively). All three tests were related to EONR; ISNT had the strongest linear relationship (r2 = 0.90) when consideration was restricted to sites on mineral soils. The ISNT and GPT were related to delta yield (maximum yield minus check yield; r2 = 0.49 and 0.60, respectively) and fertilizer response (r2 = 0.31 and 0.51, respectively). These results indicate the potential of the ISNT and GPT to account for mineralizable and residual soil N levels and thus improve current corn N recommendations in the humid southeastern USA.}, number={1}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, publisher={Soil Science Society of America}, author={Williams, Jared D. and Crozier, Carl R. and White, Jeffrey G. and Sripada, Ravi P. and Crouse, David A.}, year={2007}, pages={171–180} }
 @article{williams_crozier_white_heiniger_sripada_crouse_2007, title={Illinois soil nitrogen test predicts southeastern US corn economic optimum nitrogen rates}, volume={71}, ISSN={["0361-5995"]}, DOI={10.2136/sssaj2006.0135}, abstractNote={An accurate and quick soil N test is needed for N fertilizer recommendations for corn (Zea mays L.) for the humid southeastern USA. The Illinois soil N test (ISNT) has been used to distinguish fertilizer-responsive from unresponsive sites in Illinois. We determined relationships between economic optimum N rates (EONR) and ISNT levels in representative southeastern soils in 35 N-response trials in the Piedmont (n = 4) and Middle (n = 8) and Lower (n = 23) Coastal Plains of North Carolina from 2001 to 2004. The ISNT was strongly correlated with EONR for well or poorly drained sites (r 2 = 0.87 [n = 20] and 0.78 [n = 10], respectively); data were insuffi cient for establishing correlations for very poorly drained or severely drought-stressed sites. Expressing ISNT on a mass per unit volume basis vs. EONR improved the correlations slightly (r 2 = 0.88 and 0.79 for well and poorly drained sites, respectively), but these improvements would not justify the necessary soil bulk density determinations. Regressions of ISNT vs. minimum, average, and maximum EONR based on different N-fertilizer cost /corn price ratios (11.4:1, 7.6:1, and 5:1, respectively) showed strong correlations with EONR for well-drained sites (r 2 = 0.77, 0.87, and 0.87, respectively) and poorly drained sites (r 2 = 0.84, 0.78, 0.70, respectively). The ISNT–EONR correlations were different among the cost/price ratios for well-drained sites, but not different for poorly drained sites. Because ISNT predicted EONR robustly to different cost/price ratios, ISNT has the potential to modify or replace current N recommendation methods for corn. Abbreviations: EONR, economic optimum nitrogen rate; HM, humic matter; ISNT, Illinois soil nitrogen test; RYE, realistic yield expectation.}, number={3}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, publisher={Soil Science Society of America}, author={Williams, Jared D. and Crozier, Carl R. and White, Jeffrey G. and Heiniger, Ronnie W. and Sripada, Ravi P. and Crouse, David A.}, year={2007}, pages={735–744} }
 @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{sripada_heiniger_white_crozier_meijer_2006, title={Attempt to validate a remote sensing-based late-season corn nitrogen requirement prediction system}, ISBN={1543-7833}, journal={Crop Management}, author={Sripada, R. P. and Heiniger, R. W. and White, J. G. and Crozier, C. R. and Meijer, A. D.}, year={2006}, pages={1} }
 @article{hong_white_weisz_crozier_gumpertz_cassel_2006, title={Remote Sensing-Informed Variable-Rate Nitrogen Management of Wheat and Corn}, volume={98}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2005.0154}, abstractNote={In‐season, site‐specific, variable‐rate (SS) N management based on remote sensing (RS) may reduce N losses to groundwater while maintaining or increasing yield and N fertilizer‐use efficiency. We compared in‐season, RS‐informed N management applied on a uniform, field‐average (FA) or SS basis with the current uniform best management practice (BMP) based on “Realistic Yield Expectations” (RYE) in a typical 2‐yr southeastern U.S. coastal plain rotation: winter wheat (Triticum aestivum L.)–double‐crop soybean [Glycine max (L.) Merr.]–corn (Zea mays L.). Compared with the RYE‐based BMP, RS‐informed SS management achieved: (i) a maximum of 2.3 mg L−1 less groundwater NO3–N after 2001 wheat due to 39 kg ha−1 less fertilizer N and a 25% greater harvest N ratio (N in grain or forage/total N applied); (ii) 370 kg ha−1 more 2002 corn grain with 32 kg ha−1 greater N applied, similar harvest N ratio, and 37 kg ha−1 greater surplus N; (iii) 670 kg ha−1 more 2003 wheat grain associated with 14 kg ha−1 greater fertilizer N, 27% greater harvest N ratio, and 9 kg ha−1 less surplus N. Excepting one corn FA treatment that received excessive N, RS‐informed management produced equal or greater economic returns to N than RYE, and less surplus N for wheat. Treatments produced enduring effects on groundwater [NO3–N] consistent with agronomic results, but small relative to temporal [NO3–N] fluctuations that were positively correlated with water table elevation. To assess N management in leaching‐prone soils, frequent, periodic groundwater monitoring during and after the cropping season appears essential.}, number={2}, journal={Agronomy Journal}, publisher={American Society of Agronomy}, author={Hong, N. and White, J.G. and Weisz, R. and Crozier, C.R. and Gumpertz, M.L. and Cassel, D.K.}, year={2006}, pages={327–338} }
 @article{jordan_barnes_bogle_marshall_corbett_crozier_mclawhorn_fisher_2005, title={Influence of cultural practices and crop rotation on kenaf yield in North Carolina}, ISBN={1543-7833}, DOI={10.1094/cm-2005-0913-01-rs}, abstractNote={Kenaf is a relatively new crop to North Carolina and its impact on cropping systems has not been clearly determined. The impacts of crop rotation on kenaf, as well as the impacts of kenaf on rotation crops were examined. Crops preceding kenaf included corn, soybean, cotton, and peanut while crops following kenaf or corn included corn, soybean, cotton, peanut, and tobacco. Experiments were also conducted to define interactions among kenaf planting dates, row width/plant population systems, and cultivars. In one of two years, kenaf yield was lower when kenaf followed peanut or soybean compared to following cotton. Peanut and soybean yield were similar when following either corn and kenaf. However, corn and cotton yield was lower in one of two years when following corn compared to kenaf. Tobacco yield was similar when planted following either corn or kenaf. The interaction of planting date, row width/plant population, and cultivar was not significant for kenaf yield. No yield differences were observed between kenaf cultivars Everglade 41 and Tainung 2. Kenaf yield was higher when planted May 15 rather than June 15 and when kenaf was planted in rows spaced 8 inches apart (total plant population of 261,000 plants per acre) compared to rows spaced 36 inches apart (total plant population of 174,000 plants per acre).}, journal={Crop Management}, author={Jordan, D. L. and Barnes, J. S. and Bogle, C. R. and Marshall, T. M. and Corbett, T. and Crozier, C. R. and McLawhorn, B. and Fisher, L.}, year={2005}, pages={1} }
 @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{crozier_walls_hardy_barnes_2003, title={Tracking phosphorus response of cotton}, volume={87}, ISBN={0006-0089}, number={4}, journal={Better Crops With Plant Food}, author={Crozier, C. R. and Walls, B. and Hardy, D. H. and Barnes, J. S.}, year={2003}, pages={20} }
 @article{delaune_devai_crozier_kelle_2002, title={Sulfate reduction in Louisiana marsh soils of varying salinities}, volume={33}, ISSN={0010-3624 1532-2416}, url={http://dx.doi.org/10.1081/CSS-120002379}, DOI={10.1081/CSS-120002379}, abstractNote={Potential sulfate reduction and in situ hydrogen sulfide emission rates for three Louisiana marsh soils of varying salinities (salt, brackish, and freshwater) were used to evaluate the influence of soil physicochemical parameters on sulfur transformations in different seasons (summer, winter, and spring). Solid adsorbent preconcentration and emission flux chambers were used in field experiments to measure hydrogen sulfide emissions. Soil redox potential (Eh) was measured at depths between 5 and 50 cm. Duplicate soil cores were obtained and sectioned for laboratory analysis. The fresh and brackish marsh soils were composed predominantly of organic matter, while the salt marsh soils were composed of predominantly minerals. Fresh marsh soils were generally the most oxidized and salt marsh soils the most reduced. In situ hydrogen sulfide emissions, but not potential sulfate reduction rates, were highest for the brackish marsh. Potential sulfate reduction assays may have overestimated in-situ rates, particularly for the more oxidized fresh marsh. Sulfate turnover times were longer in the salt marsh (approximately 40 days) than in either the fresh or the brackish marshes (3–8 days). Tidal action replenishes sulfate less frequently in the fresh and brackish marshes, thus sulfate depletions are more likely. The lowest potential sulfate reduction rates for all marshes occurred in winter. This was attributed to lower temperature and decreased soil sulfate content.}, number={1-2}, journal={Communications in Soil Science and Plant Analysis}, publisher={Informa UK Limited}, author={DeLaune, Ronald D. and Devai, Istvan and Crozier, Carl R. and Kelle, Peter}, year={2002}, month={Jan}, pages={79–94} }
 @article{weisz_crozier_heiniger_2001, title={Optimizing nitrogen application timing in no-till soft red winter wheat}, volume={93}, ISSN={["0002-1962"]}, DOI={10.2134/agronj2001.932435x}, abstractNote={As no‐till acreage increases, N management guidelines need re‐examination due to the potential effects of surface residue on N transformations and crop development. Our objectives were to determine: (i) if N applied at Zadok's Growth Stage (GS) 25 improves grain yield of no‐till winter wheat (Triticum aestivum L.), (ii) if any yield increase was the result of increased spring tillering, and (iii) if there is a critical tiller density above which N application at GS‐25 in no‐till wheat was not required. Research was conducted at three sites in North Carolina with seven site‐years between fall 1996 and spring 1999. A continuum of GS‐25 tiller densities was generated (161‐1774 tillers m−2) by planting at different seeding rates and dates in a randomized complete block design. Five N treatments were applied at GS‐25, and three were applied at GS‐30. Tillering response to early spring N, yield, and yield components were measured. increasing early spring N rates resulted in higher tiller densities at GS‐30, and GS‐25 tiller density was a significant covariate. With GS‐25 tiller densities >550 tillers m−2, yields were higher when all N was applied at GS‐30. In years without spring freezes, wheat with <550 tillers m−2 achieved optimum yields when spring N was applied at GS‐25. Manipulating the timing of spring N application can optimize early spring tillering and yield component formation.}, number={2}, journal={AGRONOMY JOURNAL}, author={Weisz, R and Crozier, CR and Heiniger, RW}, year={2001}, pages={435–442} }
 @article{crozier_creamer_cubeta_2000, title={Fertilizer management impacts on stand establishment, disease, and yield of Irish potato}, volume={43}, ISSN={["1871-4528"]}, DOI={10.1007/BF02358513}, number={1}, journal={POTATO RESEARCH}, author={Crozier, CR and Creamer, NG and Cubeta, MA}, year={2000}, pages={49–59} }
 @article{cubeta_cody_sugg_crozier_2000, title={Influence of soil calcium, potassium, and pH on development of leaf tipburn of cabbage in eastern North Carolina}, volume={31}, ISSN={["1532-2416"]}, DOI={10.1080/00103620009370435}, abstractNote={Abstract Three hypotheses that involved manipulation of soil calcium (Ca), potassium (K), and pH in relation to the occurrence of leaf tipburn of cabbage in eastern North Carolina (NC) were formulated and tested: 1) adding K to soil will increase (induce) leaf tipburn; 2) adding Ca and K together to soil will block K‐related tipburn induction, and 3) raising soil pH to levels of 6.0 to 6.5 will decrease leaf tipburn. Six experiments were conducted in commercial cabbage production fields in eastern NC in 1996 and 1997 to test these hypotheses. Hypothesis 1 was accepted since higher rates of K significantly (p<0.05) increased leaf K concentration, soil K content and leaf tipburn incidence compared with the control. Total cabbage yield increased as K rates increased, however, significant differences were only observed between the control and the highest rate (365 kg K ha‐1) in 1996. Hypothesis 2 was accepted since adding increased amounts of Ca and K. did not significantly increase leaf tipburn incidence. Hypothesis 3 was rejected since a range of soil pH from 5.3 to 6.6 did not increase or decrease leaf tipburn incidence, nutrient uptake or total yield. These data suggest that leaf tipburn of cabbage can be increased (induced) with excessive K fertilization and that this practice may be associated with the disorder observed in NC. Also, the addition of Ca with K may potentially reduce the risk associated with K‐related leaf tipburn of cabbage.}, number={3-4}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, author={Cubeta, MA and Cody, BR and Sugg, RE and Crozier, CR}, year={2000}, pages={259–275} }
 @article{crozier_heiniger_bishop_1999, title={Evaluating soil compaction with a portable electronic cone penetrometer}, volume={9}, number={3}, journal={HortTechnology}, author={Crozier, C. R. and Heiniger, R. W. and Bishop, M.}, year={1999}, pages={440} }
 @article{creamer_crozier_cubeta_1999, title={Influence of seedpiece spacing and population on yield, internal quality, and economic performance of Atlantic, Superior, and Snowden potato varieties in eastern North Carolina}, volume={76}, ISSN={["0003-0589"]}, DOI={10.1007/BF02853623}, number={5}, journal={AMERICAN JOURNAL OF POTATO RESEARCH}, author={Creamer, NG and Crozier, CR and Cubeta, MA}, year={1999}, pages={257–261} }
 @article{crozier_naderman_tucker_sugg_1999, title={Nutrient and pH stratification with conventional and no-till management}, volume={30}, ISSN={["1532-2416"]}, DOI={10.1080/00103629909370184}, abstractNote={Abstract This study investigated changes in soil test results associated with sampling depths in fields managed with conventional tillage, no‐till for less than 3 years, no‐till for 3 to 6 years, and no‐till for more than 6 years. Soil samples from depths of 0–5, 0–10, 0–20, and 10–20 cm were collected from 59 fields with different tillage histories from several geologic regions, and analyzed by the North Carolina Department of Agriculture soil test laboratory. Some nutrient stratification was noted in all tillage categories. Soil test phosphorus (P), potassium (K), and zinc (Zn) concentrations were significantly higher in the 0–10 cm depth than in the 10–20 cm depth. Stratification probably results from the prevalence of tillage with disks, chisel plows or subsoilers, which do not mix the soil thoroughly. With the adoption of no‐till methods, stratification becomes even more pronounced. Our data suggest that stratification in pH, calcium (Ca), manganese (Mn), and sulfur (S) is more likely for fields in t...}, number={1-2}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, author={Crozier, CR and Naderman, GC and Tucker, MR and Sugg, RE}, year={1999}, month={Jan}, pages={65–74} }
 @article{mundy_creamer_crozier_wilson_1999, title={Potato production on wide beds: Impact on held and selected soil physical characteristics}, volume={76}, ISSN={["1874-9380"]}, DOI={10.1007/BF02910004}, number={6}, journal={AMERICAN JOURNAL OF POTATO RESEARCH}, author={Mundy, C and Creamer, NG and Crozier, CR and Wilson, LG}, year={1999}, pages={323–330} }
 @article{crozier_king_volk_1998, title={Tracing nitrogen movement in corn production systems in the North Carolina Piedmont: A nitrogen-15 study}, volume={90}, ISSN={["0002-1962"]}, DOI={10.2134/agronj1998.00021962009000020009x}, abstractNote={Abstract}, number={2}, journal={AGRONOMY JOURNAL}, author={Crozier, CR and King, LD and Volk, RJ}, year={1998}, pages={171–177} }
 @article{crozier_king_1993, title={CORN ROOT DRY-MATTER AND NITROGEN DISTRIBUTION AS DETERMINED BY SAMPLING MULTIPLE SOIL CORES AROUND INDIVIDUAL PLANTS}, volume={24}, ISSN={["0010-3624"]}, DOI={10.1080/00103629309368865}, abstractNote={Abstract Although models of nitrogen (N) flow in agroecosystems describe total plant N uptake, only limited data on roots exists. Underground dry matter and N distribution patterns in corn (Zea mays L.) were determined by isolating root segments from soil cores collected around plants at anthesis from a Typic Kanhapludult. Samples were collected from two treatments: no‐till with 70 kg N/ha and conventional tillage and planting with crimson clover (Trifolium incarnatum L.) as a N source. Seven soil cores (4.2 cm diameter) per plant were taken to recover roots in the 0‐ to 15‐cm and 15‐ to 30‐cm depth intervals. Sampling positions were at the base of the plant and at distances (perpendicular to the row) of 6, 16, and 27 cm into the trafficked interrow, and 11, 22, and 32 cm into the untrafficked interrow. Underground shoot and root segments were isolated from soil cores by hydropneumatic elutriation. Root distribution patterns in the no‐till treatment were similar in trafficked and untrafficked interrows, b...}, number={11-12}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, author={CROZIER, CR and KING, LD}, year={1993}, pages={1127–1138} }