@article{zhang_qiu_cheng_wang_liu_tu_bowman_burkey_bian_zhang_et al._2018, title={Atmospheric CO2 Enrichment and Reactive Nitrogen Inputs Interactively Stimulate Soil Cation Losses and Acidification}, volume={52}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.8b00495}, abstractNote={Reactive N inputs (Nr) may alleviate N-limitation of plant growth and are assumed to help sustain plant responses to the rising atmospheric CO2 (eCO2). However, Nr and eCO2 may elicit a cascade reaction that alters soil chemistry and nutrient availability, shifting the limiting factors of plant growth, particularly in acidic tropical and subtropical croplands with low organic matter and low nutrient cations. Yet, few have so far examined the interactive effects of Nr and eCO2 on the dynamics of soil cation nutrients and soil acidity. We investigated the cation dynamics in the plant-soil system with exposure to eCO2 and different N sources in a subtropical, acidic agricultural soil. eCO2 and Nr, alone and interactively, increased Ca2+ and Mg2+ in soil solutions or leachates in aerobic agroecosystems. eCO2 significantly reduced soil pH, and NH4+-N inputs amplified this effect, suggesting that eCO2-induced plant preference of NH4+-N and plant growth may facilitate soil acidification. This is, to our knowledge, the first direct demonstration of eCO2 enhancement of soil acidity, although other studies have previously shown that eCO2 can increase cation release into soil solutions. Together, these findings provide new insights into the dynamics of cation nutrients and soil acidity under future climatic scenarios, highlighting the urgency for more studies on plant-soil responses to climate change in acidic tropical and subtropical ecosystems.}, number={12}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Zhang, Li and Qiu, Yunpeng and Cheng, Lei and Wang, Yi and Liu, Lingli and Tu, Cong and Bowman, Dan C. and Burkey, Kent O. and Bian, Xinmin and Zhang, Weijian and et al.}, year={2018}, month={Jun}, pages={6895–6902} }
 @article{chen_yang_xia_bowman_williams_walker_shi_2018, title={The extent and pathways of nitrogen loss in turfgrass systems: Age impacts}, volume={637}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2018.05.053}, abstractNote={Nitrogen loss from fertilized turf has been a concern for decades, with most research focused on inorganic (NO3−) leaching. The present work examined both inorganic and organic N species in leachate and soil N2O emissions from intact soil cores of a bermudagrass chronosequence (1, 15, 20, and 109 years old) collected in both winter and summer. Measurements of soil N2O emissions were made daily for 3 weeks, while leachate was sampled once a week. Four treatments were established to examine the impacts of fertilization and temperature: no N, low N at 30 kg N ha−1, and high N at 60 kg N ha−1, plus a combination of high N and temperature (13 °C in winter or 33 °C in summer compared to the standard 23 °C). Total reactive N loss generally showed a "cup" pattern of turf age, being lowest for the 20 years old. Averaged across all intact soil cores sampled in winter and summer, organic N leaching accounted for 51% of total reactive N loss, followed by inorganic N leaching at 41% and N2O-N efflux at 8%. Proportional loss among the fractions varied with grass age, season, and temperature and fertilization treatments. While high temperature enhanced total reactive N loss, it had little influence on the partitioning of loss among dissolved organic N, inorganic N and N2O-N when C availability was expected to be high in summer due to rhizodeposition and root turnover. This effect of temperature was perhaps due to higher microbial turnover in response to increased C availability in summer. However when C availability was low in winter, warming might mainly affect microbial growth efficiency and therefore partitioning of N. This work provides a new insight into the interactive controls of warming and substrate availability on dissolved organic N loss from turfgrass systems.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Chen, Huaihai and Yang, Tianyou and Xia, Qing and Bowman, Daniel and Williams, David and Walker, John T. and Shi, Wei}, year={2018}, month={Oct}, pages={746–757} }
 @article{chen_xia_yang_bowman_shi_2019, title={The soil microbial community of turf: linear and nonlinear changes of taxa and N-cycling gene abundances over a century-long turf development}, volume={95}, ISSN={["1574-6941"]}, DOI={10.1093/femsec/fiy224}, abstractNote={&NA; Turf, consisting of closely spaced grasses and the subtending soil, is a unique ecosystem subject to intense management. Yet soil organic matter accumulates quickly and reaches equilibrium after 20 to 50 years. Resource availability is an important driver of species richness and theoretically their relationship is expected to be unimodal. In this work, we examined the effects of turf development (i.e. a 1, 15, 20 and 109 year‐old chronosequence) on microbial taxon richness, community composition, and abundances of genes putatively involved in N cycling through 16S rRNA gene and ITS region amplicon sequencing. Microbial alpha‐diversity remained relatively stable although soil organic C and N increased by up to 3‐fold over a century‐long turf development. However, both bacterial and fungal community compositions changed substantially from those in the previous land use, pine stands and along turf development. Youngest turf was closer to the oldest turf than to middle‐aged ones, specifically for bacterial community. Microbial changes to resource availability were also taxonomically specific. The relative abundance of Proteobacteria was independent of resource availability; Nitrospirae increased monotonically, and Bacteroidetes, Actinobacteria and Glomeromycota varied curvilinearly. However, abundances of most taxa from the phylum to operational taxonomic unit level and N‐cycling genes varied nonlinearly with turf development. &NA; Graphical Abstract Figure. Turf, an apparent copiotrophic environment, harbors diverse microbial taxa; the abundances of most taxa from the phylum to operational taxonomic unit level changed nonlinearly along turf development.}, number={2}, journal={FEMS MICROBIOLOGY ECOLOGY}, author={Chen, Huaihai and Xia, Qing and Yang, Tianyou and Bowman, Daniel and Shi, Wei}, year={2019}, month={Feb} }
 @article{pinnix_miller_bowman_grabow_2018, title={Color, Transfer, and Application Parameters of Turfgrass Colorants}, volume={110}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2017.03.0164}, abstractNote={Core Ideas
Turf colorants can be used as an alternative to winter overseeding, therefore saving turf managers resources.Multidimensional scaling analysis can be used to separate turf colorants into groups, allowing turf managers to better select products based on color parameters.Turf colorant transfer varies greatly among products and can result in severe staining.
Turfgrass colorants are primarily used as an alternative to winter overseeding. Information on colorants is limited in the scientific literature. The primary objective of this field study was to evaluate the effect turfgrass colorants had on color parameters (colorant intensity, color, and hue angle) of dormant bermudagrass (Cynodon sp.). Secondary objectives were to examine colorant transfer (wipe off) from the turfgrass surface to an absorbent material and to measure product viscosities. Twenty‐five colorants were applied at two spray volumes (75 and 112 mL m–2) on dormant bermudagrass at two heights of cut (0.3 and 1.5 cm). Multidimensional scaling and cluster analysis were used to separate colorants based on measured color parameters. Group 1 colorants maintained colorant intensity the longest, but colorant color was reduced at application due to the appearance of bright blue (e.g., Munsell 5BG/6/6) and bright green (e.g., Munsell 7.5GY/7/10) colors. Group 2 colorants provided the darkest green (e.g., Munsell 5GY/4/4) color, while Group 3 colorants provided minimal color change of dormant turfgrass. Among the Group 2 colorants, Green Lawnger, Lesco Green, Ultradwarf Super, Southwest Green, and Endurant provided a natural green color. Measurements of colorant transfer showed that Blue, Regreen, SprayMax, Green Dye Turf, Titan Green Turf, Solarogen, and Endurant have the highest propensity to disassociate from treated turfgrass. The use of multidimensional scaling and cluster analysis provided new information regarding a number of turf colorants. Grouping products by measured parameters indicated that products within Group 2 provided superior performance.}, number={1}, journal={AGRONOMY JOURNAL}, author={Pinnix, Garland D. and Miller, Grady L. and Bowman, Daniel C. and Grabow, Garry L.}, year={2018}, pages={66–76} }
 @article{sermons_wherley_zhang_bowman_rufty_2017, title={The role of internal and external nitrogen pools in bermudagrass growth during spring emergence from dormancy}, volume={40}, ISSN={["1532-4087"]}, DOI={10.1080/01904167.2016.1264424}, abstractNote={ABSTRACT As bermudagrass (Cynodon dactylon (L.) Pers.) transitions from winter dormancy to active growth in spring, nitrogen is essential for new tissue growth. We examined the relative contributions of internally stored nitrogen and that taken up by preexisting and newly produced roots. Field-collected dormant bermudagrass was transferred to a nutrient solution culture system in a growth chamber. Cultures were provided either a non-nitrogen-containing solution or one amended with nitrate labeled with the 15N isotope of nitrogen, which allowed tracking of endogenous and exogenous N pools in all tissues as growth began. Nitrogen in stolon internodes was the largest N source for early growth. Though mass increased at the same rate in both N treatments over 3 weeks of growth, the unfertilized treatment showed early signs of nitrogen deficiency: low tissue N, slowed leaf elongation, and fewer but longer roots. Preexisting roots were active in absorption almost immediately; new roots were produced quickly and had even higher N uptake rates.}, number={10}, journal={JOURNAL OF PLANT NUTRITION}, author={Sermons, Shannon M. and Wherley, Benjamin G. and Zhang, Chenxi and Bowman, Daniel C. and Rufty, Thomas W.}, year={2017}, pages={1404–1416} }
 @article{lu_bowman_rufty_shi_2015, title={Reactive Nitrogen in Turfgrass Systems: Relations to Soil Physical, Chemical, and Biological Properties}, volume={44}, ISSN={["1537-2537"]}, DOI={10.2134/jeq2014.06.0247}, abstractNote={Turfgrass systems contribute to the loading of reactive N to water and air via runoff, leaching, and gas emission. Yet, a comprehensive approach has never been developed to assess N loss potential from turfgrass systems. We used pools and production of reactive N (inorganic N, extractable organic N, and NO) to estimate N loss potential and hypothesized that this potential could be predicated by basic soil properties. A total of 68 soil samples were taken from 17 bermudagrass sites in North Carolina. Basic soil properties were analyzed, including soil C and N, C:N ratio, microbial biomass, moisture, pH, and percent silt/clay/sand. Soil samples varied most widely in texture, followed by soil C and N, microbial biomass, moisture, pH, and C:N ratio. The pools of extractable organic N and inorganic N were comparable, indicating that soluble organic N should be considered as a pathway of N loss from turfgrass. Turfgrass with large pools and production of reactive N was characterized by high soil C and N, microbial biomass, and moisture. Because soil C and N accumulate over time after turfgrass establishment, turfgrass age could be a suitable practical indicator of N loss potential and thus could be used to implement changes in management. Pools and production of reactive N in liquid and gas phases were well correlated, suggesting that if a turfgrass system has a high potential of N loss via leaching and runoff, it may also be of a high potential for NO emissions.}, number={1}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Lu, Caiyan and Bowman, Daniel and Rufty, Thomas and Shi, Wei}, year={2015}, pages={210–218} }
 @article{nautiyal_grabow_huffman_miller_bowman_2015, title={Residential Irrigation Water Use in the Central Piedmont of North Carolina. I: Measured Use and Water Requirements}, volume={141}, ISSN={["1943-4774"]}, DOI={10.1061/(asce)ir.1943-4774.0000819}, abstractNote={AbstractIrrigation is the most common and standard practice for maintaining turfgrass and landscape plants in residential settings. The main objective of this study was to quantify the residential irrigation water use in Cary, North Carolina. A subobjective was to develop distributions of monthly reference evapotranspiration (ETo) and gross irrigation requirements (GIRs) for the area using long-term weather data. As part of the subobjective, an investigation was performed to compare daily measured solar radiation with two empirical methods of estimating solar radiation (Rs). The goal of this investigation was to determine the relative accuracy of these methods and to evaluate the impact of using Rs estimates in the computation of ETo and GIR for the Raleigh-Durham area, where Cary is located. Irrigation water use data from 2005 to 2007 for 120 randomly sampled residences were evaluated. The average lawn area of the sampled residences was 713  m2. None of the sampled households used drip irrigation. A nega...}, number={4}, journal={JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING}, author={Nautiyal, M. and Grabow, G. L. and Huffman, R. L. and Miller, G. L. and Bowman, D.}, year={2015}, month={Apr} }
 @article{nautiyal_grabow_huffman_miller_bowman_2015, title={Residential Irrigation Water Use in the Central Piedmont of North Carolina. II: Evaluation of Smart Irrigation Technologies}, volume={141}, ISSN={["1943-4774"]}, DOI={10.1061/(asce)ir.1943-4774.0000820}, abstractNote={AbstractA study was conducted in Cary, North Carolina, in the spring and summer of 2009 with the purpose of evaluating the effectiveness of two “smart irrigation” controllers based on the amount of irrigation applied and resulting turf quality in residential settings. Twenty-four residential sites were selected, in clusters of four, representing six geographical areas within the town. Each geographical cluster included one site of each treatment. The treatments were standard irrigation controller with an add-on soil moisture sensor system (SMS); standard irrigation controller with an add-on evapotranspiration-based adjustment system (ET); standard irrigation controller using seasonal runtimes based on historical climate data (ED); and a control group which used a standard irrigation controller with no intervention (CON). Weekly water usage was obtained from irrigation meter readings and turf quality was characterized using a visual rating and a normalized difference vegetation index (NDVI) meter. Maximum ...}, number={4}, journal={JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING}, author={Nautiyal, M. and Grabow, G. L. and Huffman, R. L. and Miller, G. L. and Bowman, D.}, year={2015}, month={Apr} }
 @article{zhang_miller_rufty_bowman_2013, title={Nitrate Leaching from Two Kentucky Bluegrass Cultivars as Affected by Nitrate Uptake Capacity and Subsurface Soil Compaction}, volume={53}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2012.10.0600}, abstractNote={ABSTRACTThere are a number of strategies to minimize NO3– leaching from turfgrass, including planting turfgrass cultivars with higher NO3– absorption abilities. This column lysimeter study was conducted to examine NO3– leaching from two Kentucky bluegrass (Poa pratensis L.) cultivars differing in NO3– uptake capacity. Subsurface soil compaction was included as a second factor. Tillers of Julia and Midnight Kentucky bluegrass, previously identified as having high and low NO3– uptake capacity, respectively, were grown in column lysimeters. Each column was filled with Wagram loamy sand with or without a subsurface compaction layer 8.5 cm below the surface. The two cultivars were established and then treated to impose moderate N deficiency. Potassium nitrate was applied in solution at 49 kg N ha–1 followed by daily heavy irrigation. Leachate was collected and analyzed for NO3–‐N. Cumulative N leaching loss of applied N ranged from 2.6 to 19% and 2.8 to 21% for Julia and Midnight, respectively. In two out of three trials, both cultivars absorbed NO3– very efficiently in noncompacted soil, with only trace amounts of NO3– leaching. While NO3–‐N loss averaged 4.7% of applied N in noncompacted soil across all trials, subsurface soil compaction increased that to 8.9%. Results indicated that despite being identified as more efficient for NO3– uptake, NO3– leaching from Julia was generally similar to that from Midnight. Soil conditions and differences in root morphology and/or architecture may played a more important role than root uptake capacity in determining NO3– leaching from these Kentucky bluegrass genotypes.}, number={4}, journal={CROP SCIENCE}, author={Zhang, Chenxi and Miller, Grady L. and Rufty, Thomas W. and Bowman, Daniel C.}, year={2013}, pages={1722–1733} }
 @article{zhang_rufty_miller_bowman_2013, title={Nitrate Uptake Rates of Kentucky Bluegrass Genotypes and Their Effect on Nitrate Absorption under Competitive Conditions}, volume={53}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2012.10.0597}, abstractNote={ABSTRACTNitrate leaching from turfgrasses continues to be a concern. It is proposed that selecting turfgrass genotypes with higher NO3− absorption abilities could reduce NO3− leaching. This study examined the intraspecific difference in NO3− absorption among Kentucky bluegrass (Poa pratensis L.) genotypes and how such a difference affects N absorption when roots are in competition for soil N. A nutrient solution screening procedure was used to identify Kentucky bluegrass genotypes having high vs. low NO3− uptake capacity. Tillers of 60 Kentucky bluegrass cultivars were rooted and transferred to a continuous flow solution culture system. After establishment, plants were treated to develop moderate N deficiency. Isotopically labeled (15N) KNO3 was introduced at high (1 mM) and low (0.05 mM) concentrations to screen for differences in NO3− uptake. After a brief uptake period, plants were harvested, dried, and analyzed for 15N content to determine N uptake rate. There were significant differences among genotypes for uptake rate at both high and low N concentrations. The 60 genotypes exhibited a wide range of uptake rates, with strong correlation between rates at high and low N. The cultivars Julia and Midnight were selected as representing cultivars with efficient and inefficient NO3− uptake, respectively. Julia had NO3− uptake rates averaging 56% higher than Midnight. A subsequent lysimeter study examined whether higher NO3− uptake capacity would translate into increased N absorption under competitive conditions. Tillers of the two cultivars were planted as a mixed stand in soil or sand column lysimeters. After establishment, 15N‐labeled KNO3 solution at high (2 or 1mM) and low (0.05mM) concentrations was applied to each column. After an uptake period, individual plants of each cultivar were harvested for 15N analysis. Results indicated that Julia absorbed 20 to 50% more NO3− than Midnight at the high N concentration and 25 to 71% more NO3− more than Midnight at the low N concentration. Most differences were statistically significant. This indicates that differences in NO3− absorption by Kentucky bluegrass identified in solution culture translate into differences in absorption of soil N.}, number={3}, journal={CROP SCIENCE}, author={Zhang, Chenxi and Rufty, Thomas W. and Miller, Grady L. and Bowman, Daniel C.}, year={2013}, month={May}, pages={1179–1188} }
 @article{li_hu_bowman_shi_2013, title={Nitrous oxide production in turfgrass systems: Effects of soil properties and grass clipping recycling}, volume={67}, ISSN={0929-1393}, url={http://dx.doi.org/10.1016/J.APSOIL.2013.03.002}, DOI={10.1016/J.APSOIL.2013.03.002}, abstractNote={Soil N2O emissions can affect global environments because N2O is a potent greenhouse gas and ozone depletion substance. In the context of global warming, there is increasing concern over the emissions of N2O from turfgrass systems. It is possible that management practices could be tailored to reduce emissions, but this would require a better understanding of factors controlling N2O production. In the present study we evaluated the spatial variability of soil N2O production and its correlation with soil physical, chemical and microbial properties. The impacts of grass clipping addition on soil N2O production were also examined. Soil samples were collected from a chronosequence of three golf courses (10, 30, and 100-year-old) and incubated for 60 days at either 60% or 90% water filled-pore space (WFPS) with or without the addition of grass clippings or wheat straw. Both soil N2O flux and soil inorganic N were measured periodically throughout the incubation. For unamended soils, cumulative soil N2O production during the incubation ranged from 75 to 972 ng N g−1 soil at 60% WFPS and from 76 to 8842 ng N g−1 soil at 90% WFPS. Among all the soil physical, chemical and microbial properties examined, soil N2O production showed the largest spatial variability with the coefficient of variation ~110% and 207% for 60% and 90% WFPS, respectively. At 60% WFPS, soil N2O production was positively correlated with soil clay fraction (Pearson's r = 0.91, P < 0.01) and soil NH4+–N (Pearson's r = 0.82, P < 0.01). At 90% WFPS, however, soil N2O production appeared to be positively related to total soil C and N, but negatively related to soil pH. Addition of grass clippings and wheat straw did not consistently affect soil N2O production across moisture treatments. Soil N2O production at 60% WFPS was enhanced by the addition of grass clippings and unaffected by wheat straw (P < 0.05). In contrast, soil N2O production at 90% WFPS was inhibited by the addition of wheat straw and little influenced by glass clippings (P < 0.05), except for soil samples with >2.5% organic C. Net N mineralization in soil samples with >2.5% organic C was similar between the two moisture regimes, suggesting that O2 availability was greater than expected from 90% WFPS. Nonetheless, small and moderate changes in the percentage of clay fraction, soil organic matter content, and soil pH were found to be associated with large variations in soil N2O production. Our study suggested that managing soil acidity via liming could substantially control soil N2O production in turfgrass systems.}, journal={Applied Soil Ecology}, publisher={Elsevier BV}, author={Li, Xuechao and Hu, Feng and Bowman, Daniel and Shi, Wei}, year={2013}, month={May}, pages={61–69} }
 @article{campbell_chee_lubbers_bowman_meredith_johnson_fraser_bridges_jones_2012, title={Dissecting Genotype x Environment Interactions and Trait Correlations Present in the Pee Dee Cotton Germplasm Collection following Seventy Years of Plant Breeding}, volume={52}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2011.07.0380}, abstractNote={ABSTRACTGenotype × environment (G × E) interactions and trait correlations significantly impact efforts to develop high‐yield, high‐quality, and environmentally stable Upland cotton (Gossypium hirsutum L.) cultivars. Knowledge of both can and should be used to design optimal breeding programs and effective selection criteria. In this study, we examined the G × E interactions and trait correlations present in the 70‐yr Pee Dee cotton germplasm enhancement program. Since beginning in 1935, the Pee Dee program has employed a variety of unique germplasm and breeding methods to release >80 improved germplasm lines and cultivars. Results suggest that significant G × E interactions exist for several agronomic and fiber quality performance traits that are mostly due to changes in magnitude. Negative genotypic correlations still persist between lint percent/lint yield and fiber length/fiber strength. However, apparently the breeding methods and selection criteria used over 70 yr have lessened the negative relationship between agronomic performance and fiber quality over time to some degree. The results provide cotton breeders a resource to select specific Pee Dee germplasm lines for increased environmental stability. Cotton breeders can also use the information herein to select specific Pee Dee germplasm lines that represent rare recombination events that combine high yield and fiber quality potential.}, number={2}, journal={CROP SCIENCE}, author={Campbell, B. T. and Chee, P. W. and Lubbers, E. and Bowman, D. T. and Meredith, W. R., Jr. and Johnson, J. and Fraser, D. and Bridges, W. and Jones, D. C.}, year={2012}, pages={690–699} }
 @article{briscoe_miller_brinton_bowman_peacock_2012, title={Evaluation of 'Miniverde' bermudagrass and 'Diamond' zoysiagrass putting green establishment using granular Fertilizer Applications}, volume={47}, number={7}, journal={HortScience}, author={Briscoe, K. and Miller, G. and Brinton, S. and Bowman, D. and Peacock, C.}, year={2012}, pages={943–947} }
 @article{grabow_ghali_huffman_miller_bowman_vasanth_2013, title={Water Application Efficiency and Adequacy of ET-Based and Soil Moisture-Based Irrigation Controllers for Turfgrass Irrigation}, volume={139}, ISSN={["1943-4774"]}, DOI={10.1061/(asce)ir.1943-4774.0000528}, abstractNote={Abstract Increasing competition for water and the desire for high-quality turfgrass require sound irrigation water management. The main objective of this study was to evaluate two types of commercially available irrigation control technologies: one based on evapotranspiration (ET) estimates and the other based on feedback from a soil-moisture sensor (SMS). Irrigation treatments were combinations of controller technology: a timer-based standard controller system (TIM), an add-on (1 set point) SMS system (SMS1), and an evapotranspiration (ET)-based system (ETB), and watering frequency: weekly, twice per week, and daily (1, 2, and 7 days per week, respectively) plus a 10th treatment of an on-demand (2 set point) SMS system (SMS2). Both irrigation efficiency and adequacy were best for the SMS2 treatment when averaged over all three years. The SMS1 treatment provided good irrigation efficiency, but irrigation adequacy suffered, most noticeably with the twice per week treatment. The ET treatment provided good i...}, number={2}, journal={JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING}, author={Grabow, G. L. and Ghali, I. E. and Huffman, R. L. and Miller, G. L. and Bowman, D. and Vasanth, A.}, year={2013}, month={Feb}, pages={113–123} }
 @article{wherley_bowman_shi_rufty_2011, title={Effect of soil saturation on development and 15N-Nitrate uptake efficiency of two warm season grasses emerging from dormancy}, volume={34}, ISSN={0190-4167 1532-4087}, url={http://dx.doi.org/10.1080/01904167.2011.610489}, DOI={10.1080/01904167.2011.610489}, abstractNote={Use of effluent on turfgrass is increasing due to population growth and limited water supplies. Because effluent is generated continuously, turf managers may be forced to over-irrigate, leading to soil saturation. Although the nutrients in effluent are readily absorbed by turf, the effects of prolonged soil saturation on uptake are unknown. This research examined the impact of soil saturation on plant development and nitrate uptake of two warm-season turfgrasses emerging from dormancy. Dormant grass/soil cores of hybrid bermudagrass and common centipedegrass were treated to stimulate regrowth, with soil moisture controlled at saturation (∼0.36 cm3 cm−3) or field capacity (0.13 cm3 cm−3). Soil saturation reduced canopy development in both species, but shoot biomass was affected only in bermudagrass. Nitrate uptake by both species was generally unaffected by soil saturation. While extended periods of soil saturation may alter plant development, they do not impair the ability of these turfgrasses to absorb nitrogen.}, number={13}, journal={Journal of Plant Nutrition}, publisher={Informa UK Limited}, author={Wherley, Benjamin and Bowman, Daniel and Shi, Wei and Rufty, Thomas, Jr.}, year={2011}, month={Oct}, pages={2039–2054} }
 @article{yao_bowman_shi_2011, title={Seasonal variations of soil microbial biomass and activity in warm- and cool-season turfgrass systems}, volume={43}, ISSN={["0038-0717"]}, DOI={10.1016/j.soilbio.2011.03.031}, abstractNote={Plant growth can be an important factor regulating seasonal variations of soil microbial biomass and activity. We investigated soil microbial biomass, microbial respiration, net N mineralization, and soil enzyme activity in turfgrass systems of three cool-season species (tall fescue, Festuca arundinacea Schreb., Kentucky bluegrass, Poa pratensis L., and creeping bentgrass, Agrostis palustris L.) and three warm-season species (centipedegrass, Eremochloa ophiuroides (Munro.) Hack, zoysiagrass, Zoysia japonica Steud, and bermudagrass, Cynodon dactylon (L.) Pers.). Microbial biomass and respiration were higher in warm- than the cool-season turfgrass systems, but net N mineralization was generally lower in warm-season turfgrass systems. Soil microbial biomass C and N varied seasonally, being lower in September and higher in May and December, independent of turfgrass physiological types. Seasonal variations in microbial respiration, net N mineralization, and cellulase activity were also similar between warm- and cool-season turfgrass systems. The lower microbial biomass and activity in September were associated with lower soil available N, possibly caused by turfgrass competition for this resource. Microbial biomass and activity (i.e., microbial respiration and net N mineralization determined in a laboratory incubation experiment) increased in soil samples collected during late fall and winter when turfgrasses grew slowly and their competition for soil N was weak. These results suggest that N availability rather than climate is the primary determinant of seasonal dynamics of soil microbial biomass and activity in turfgrass systems, located in the humid and warm region.}, number={7}, journal={SOIL BIOLOGY & BIOCHEMISTRY}, author={Yao, Huaiying and Bowman, Daniel and Shi, Wei}, year={2011}, month={Jul}, pages={1536–1543} }
 @article{carley_goodman_sermons_shi_bowman_miller_rufty_2011, title={Soil Organic Matter Accumulation in Creeping Bentgrass Greens: A Chronosequence with Implications for Management and Carbon Sequestration}, volume={103}, ISSN={1435-0645}, url={http://dx.doi.org/10.2134/agronj2010.0335}, DOI={10.2134/agronj2010.0335}, abstractNote={Excessive organic matter (OM) accumulation in creeping bentgrass (Agrostis palustris Huds.) putting greens, and its restriction of permeability, is one of the most difficult problems in turfgrass management. In this transition zone study, we characterized temporal and spatial aspects of OM accumulation, in an attempt to assess the effectiveness of management and to begin to uncover the processes controlling C sequestration. Root zone samples were collected from sand‐based putting greens at 49 golf courses of various ages, generating 212 individual observations. Organic matter accumulated hyperbolically over time in the top 2.5 cm; apparent critical levels of 40 g kg−1 were exceeded within 5 yr. At a depth of 2.5 to 7.6 cm, accumulation was much slower and linear over time, and critical levels were not reached even after 20 yr. Oxygen levels were never depressed more than 15%, indicating that intensive management of the upper soil profile was successfully allowing gas exchange into the root zone. Carbon accumulated in the soil profile hyperbolically, reflecting changes in the large OM pool near the soil surface. The sequestration rate of 59 g m−2 yr−1 over 25 yr was less than that observed by others examining soil under bentgrass greens in different environments. The evidence indicates that OM and C accumulation are strongly influenced by increasing microbial degradation rates as turfgrass systems age.}, number={3}, journal={Agronomy Journal}, publisher={American Society of Agronomy}, author={Carley, Danesha Seth and Goodman, David and Sermons, Shannon and Shi, Wei and Bowman, Dan and Miller, Grady and Rufty, Thomas}, year={2011}, pages={604} }
 @article{matthieu_bowman_thapa_cassel_rufty_2011, title={Turfgrass Root Response to Subsurface Soil Compaction}, volume={42}, ISSN={["1532-2416"]}, DOI={10.1080/00103624.2011.622826}, abstractNote={Soil compaction prevents turfgrass roots from growing deep into the soil and may limit access to water and nutrients. The objective of this study was to characterize the ability of turfgrass roots to penetrate a compacted subsurface layer. Seven turfgrasses were grown in soil columns. Each column was divided into three sections with the top and bottom packed to a bulk density of 1.6 g cm−3, and the middle (treatment) layer packed to 1.6, 1.7, 1.8, 1.9, or 2.0 g cm−3. Subsurface compaction reduced root mass for two of the species, and inhibited deep root growth in all seven species, with the greatest reduction occurring between 1.7 and 1.8 g cm−3. There appears to be little difference between species in ability to penetrate compacted soils, suggesting that soil preparation and routine management practices, rather than grass selection, is the more viable way to handle soil compaction problems in turf.}, number={22}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, author={Matthieu, Donald E. and Bowman, Daniel C. and Thapa, Bir B. and Cassel, D. Keith and Rufty, Thomas W.}, year={2011}, pages={2813–2823} }
 @article{arya_heitman_thapa_bowman_2010, title={Predicting Saturated Hydraulic Conductivity of Golf Course Sands from Particle-Size Distribution}, volume={74}, ISSN={["1435-0661"]}, DOI={10.2136/sssaj2009.0022}, abstractNote={This research developed a model of saturated hydraulic conductivity for golf course and athletic field media. The model was developed from saturated flow data in packed sand cores, for which a pore‐size distribution was derived from particle‐size distribution, bulk density, and measured soil water characteristic data. The pores were first assumed to form an idealized structure, consisting of non‐tortuous capillary tubes of uniform shape and size, and the Hagen–Poiseuille flow equation was applied to compute idealized saturated flow. The idealized saturated flows were compared with saturated flows derived from the measured saturated hydraulic conductivity data. Subsequently, an empirical relationship was established between the two in the form: Qt(m) = c + dQt(h–p), where Qt(m) is the saturated flow through the natural‐structure sand cores and Qt(–p) is the saturated flow through the idealized pore structure for the same core. In our study, parameters c and d had values of −1.675 and 0.308, respectively, and the r2 of the regression had a value of 0.871. The model was applied to 14 golf course sands and produced excellent results with minor anomalies.}, number={1}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Arya, Lalit M. and Heitman, J. L. and Thapa, B. B. and Bowman, D. C.}, year={2010}, pages={33–37} }
 @article{dell_bowman_rufty_shi_2010, title={The community composition of soil-denitrifying bacteria from a turfgrass environment}, volume={161}, ISSN={["1769-7123"]}, DOI={10.1016/j.resmic.2010.03.010}, abstractNote={Soil-denitrifying bacteria in highly-managed turfgrass systems were examined to assess their response to land-use change and time under management. Denitrifier community composition and diversity in a turfgrass chronosequence of 1 to 95-years-old were compared with those in an adjacent pine-dominant forest via molecular investigations of nirK and nosZ gene fragments. Both denaturing gradient gel electrophoresis and sequenced clone libraries revealed that the denitrifier community became more diverse after turf establishment, and the diversity was then preserved. Furthermore, the composition of the turfgrass denitrifier community was slightly affected by time under management. Meta-analysis of sequenced nirK and nosZ gene fragments from a variety of ecosystems showed that denitrifier communities in pine and turf were more similar to those in other environments than to each other, suggesting that land-use change substantially modified the composition and increased the diversity of denitrifiers. This study provides a useful baseline of nirK- and nosZ-type soil denitrifier communities to aid in the evaluation of ecological and environmental impacts of turfgrass systems.}, number={5}, journal={RESEARCH IN MICROBIOLOGY}, author={Dell, Emily A. and Bowman, Daniel and Rufty, Thomas and Shi, Wei}, year={2010}, month={Jun}, pages={315–325} }
 @article{wherley_shi_bowman_rufty_2009, title={Fate of N-15-Nitrate Applied to a Bermudagrass System: Assimilation Profiles in Different Seasons}, volume={49}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2008.08.0468}, abstractNote={ABSTRACTPressures to protect water quality and water shortages are leading to increased applications of effluent water on turfgrasses, and there are pressures to disperse effluent throughout the year. These experiments investigated NO3− uptake efficiency by Tifway bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy] during growth and dormancy cycles, and thus the potential to filter effluent at different times of the year. Turf–soil cores from field plots were placed in controlled environment chambers and fed solutions with 15N‐NO3− Nitrate uptake was, as expected, greatest in summer when plants were growing rapidly. Less than 10% of applied NO3− was recovered from soil after 3 d. The microbial population was elevated, but little 15N was found in soil microbial or organic fractions. The system was inefficient in winter when bermudagrass was dormant; 80 to 90% of the NO3− remained in soil after 16 d. The system was more efficient than expected in spring and fall transition months, with 80 to 90% assimilated within 1 wk. A large portion of applied 15N was held belowground in rhizomes and roots. Competitiveness of the microbial population was greater in transition months than during rapid bermudagrass growth in August when the population itself was larger. Although seasonal differences occurred, bermudagrass roots were consistently more competitive than the microbial population for applied 15N, an observation very different from that with other grass systems.}, number={6}, journal={CROP SCIENCE}, author={Wherley, Benjamin G. and Shi, Wei and Bowman, Daniel C. and Rufty, Thomas W.}, year={2009}, pages={2291–2301} }
 @article{yao_bowman_rufty_shi_2009, title={Interactions between N fertilization, grass clipping addition and pH in turf ecosystems: Implications for soil enzyme activities and organic matter decomposition}, volume={41}, ISSN={0038-0717}, url={http://dx.doi.org/10.1016/j.soilbio.2009.03.020}, DOI={10.1016/j.soilbio.2009.03.020}, abstractNote={Turf has been acknowledged as an important ecosystem with potential for soil C sequestration. As a major process dictating soil C storage, organic matter decomposition has received little attention in turf systems. Given that soil enzyme-catalyzed biochemical reactions are the rate limiting steps of organic matter decomposition, we examined the activities of oxidative and hydrolytic soil enzymes and their relations with soluble organic compounds and soil C and N mineralization in two turf chronosequences with contrasting soil pH and in response to N fertilization and grass clipping addition. In comparison with turf ecosystems under acidic soil, phenol oxidase activity was about two-fold greater in turf ecosystems under alkaline soil and positively correlated to about two-fold differences in soluble phenolics and dissolved organic C between alkaline and acidic soils. However, the activities of hydrolytic enzymes including cellulase, chitinase, and glucosidase were lower in alkaline soil. It appears that the high concentration of soluble phenolics inhibited the activities of hydrolytic enzymes that in turn limited the decomposition of dissolved organic C and resulted in its accumulation in alkaline soil. Nitrogen mineralization was comparable between alkaline and acidic soils, but CO2 evolution was about two-fold greater in alkaline soil, possibly due to considerable abiotic carbonate dissolution. We observed that mineral N input at 60 mg N kg−1 soil had very minor negative effects on the activities of both phenol oxidase and hydrolytic enzymes. Grass clipping addition did not affect the activity of phenol oxidase, but increased the activities of soil chitinase, cellulase, glucosidase, and glucosaminidase by up to 20% and also soluble phenolics in soil by about 10%. Our results suggest that soil phenol oxidase might regulate the activities of hydrolytic soil enzymes via its control on soluble phenolics and function as an 'enzymatic latch' to hold soil organic C in highly managed turf ecosystems. While soil pH is important to affect phenol oxidase activity and therefore decomposition, management practices, i.e., N fertilization and grass clipping addition may indirectly affect the decomposition through enhancing turfgrass productivity and thus soil C input.}, number={7}, journal={Soil Biology and Biochemistry}, publisher={Elsevier BV}, author={Yao, Huaiying and Bowman, Daniel and Rufty, Thomas and Shi, Wei}, year={2009}, month={Jul}, pages={1425–1432} }
 @inproceedings{grabow_vasanth_bowman_huffman_miller_2008, title={Evaluation of Evapotranspiration-Based and Soil-Moisture-Based Irrigation Control in Turf}, ISBN={9780784409763}, url={http://dx.doi.org/10.1061/40976(316)117}, DOI={10.1061/40976(316)117}, abstractNote={A study was initiated in Fall 2006 in Raleigh, North Carolina to compare two types of commercially available irrigation control technologies, one based on estimates of evapotranspiration (ET) and the other based on feedback from soil moisture sensors. Water applied and turf quality from one ET-based system and two sensor-based systems were compared to a system using a standard time-based irrigation schedule. The effect of irrigation frequency was also a part of the study. Estimates of turf ET were obtained from the Penman-Monteith equation using on-site weather data, and also from an atmometer. Results from the twenty week evaluation in 2007 showed that on average the “add-on” soil-moisture-based system evaluated applied the least amount of water while the ETbased system evaluated applied the most water. Weekly irrigation frequencies used the least amount of water, followed by bi-weekly and daily frequencies in increasing amounts when averaged across all technologies. Minimally acceptable turf quality was maintained by all technologies and frequencies through most of the study, but turf quality declined substantially the last month of the study for the add-on system and standard timer-based system. The “on-demand” sensor-based system resulted in the best combination of water efficiency and turf quality.}, booktitle={World Environmental and Water Resources Congress 2008}, publisher={American Society of Civil Engineers}, author={Grabow, Garry L. and Vasanth, Arjun and Bowman, Dan and Huffman, Rodney L. and Miller, Grady L.}, year={2008}, month={May} }
 @article{devitt_wright_bowman_morris_lockett_2008, title={Nitrate-N concentrations in the soil solution below reuse irrigated golf course fairways}, volume={43}, number={7}, journal={HortScience}, author={Devitt, D. A. and Wright, L. and Bowman, D. C. and Morris, R. L. and Lockett, M.}, year={2008}, pages={2196–2202} }
 @article{place_bowman_burton_rutty_2008, title={Root penetration through a high bulk density soil layer: differential response of a crop and weed species}, volume={307}, ISSN={["1573-5036"]}, DOI={10.1007/s11104-008-9594-4}, number={1-2}, journal={PLANT AND SOIL}, author={Place, George and Bowman, Daniel and Burton, Michael and Rutty, Thomas}, year={2008}, month={Jun}, pages={179–190} }
 @article{arya_bowman_thapa_cassel_2008, title={Scaling soil water characteristics of golf course and athletic field sands from particle-size distribution}, volume={72}, ISSN={["0361-5995"]}, DOI={10.2136/sssaj2006.0232}, abstractNote={The soil water characteristic (SWC) of sands is an important hydraulic parameter in designing golf courses and athletic fields. A modified version of the Arya–Paris model of the soil water characteristic was adapted to 14 golf course media that contained no to minor amounts of clay and silt. In this model, the particle‐size distribution curve is divided into a number of fractions and the natural pore length, Li(n), is scaled using the diameter of spherical particles as the length unit. The scaled pore length is given by 2Ri, where ni is the number of spherical particles in the ith fraction, 2Ri is the particle diameter, and αi is the scaling parameter, which is calculated using the relationship log= a + blogni Although the model adapted well, there were concerns about the sensitivity of predicted SWCs to uncertainties in parameters a and b Consequently, we developed and evaluated a procedure to predict Li(n) directly from straight pore lengths, Li(c) in counterpart cubic close‐packed assemblages of spherical particles, using the relationship logLi(n) = c + dlogLi(c) Predicted pressure heads using both procedures were similar with best‐fit parameters. When uncertainties were imposed on Parameters a, b and c, d, however, SWCs using the latter procedure showed far less sensitivity, as measured by the root mean square residuals (RMSRs). In addition, for sand materials grouped together on the basis of similarity in particle‐size distribution and bulk density, replacing individual best‐fit parameters by the group mean parameters did not have significant effects on predicted pressure heads.}, number={1}, journal={SOIL SCIENCE SOCIETY OF AMERICA JOURNAL}, author={Arya, Lalit A. and Bowman, Daniel C. and Thapa, Bir B. and Cassel, D. Keith}, year={2008}, pages={25–32} }
 @article{wallace_bowman_campbell_chee_gutierrez_kohel_mccarty_myers_percy_robinson_et al._2009, title={Status of the USA cotton germplasm collection and crop vulnerability}, volume={56}, ISSN={["1573-5109"]}, DOI={10.1007/s10722-008-9382-2}, number={4}, journal={GENETIC RESOURCES AND CROP EVOLUTION}, author={Wallace, T. P. and Bowman, D. and Campbell, B. T. and Chee, P. and Gutierrez, O. A. and Kohel, R. J. and McCarty, J. and Myers, G. and Percy, R. and Robinson, F. and et al.}, year={2009}, month={Jun}, pages={507–532} }
 @article{dell_bowman_rufty_shi_2008, title={Intensive management affects composition of betaproteobacterial ammonia oxidizers in turfgrass systems}, volume={56}, ISSN={["1432-184X"]}, DOI={10.1007/s00248-007-9335-x}, abstractNote={Turfgrass is a highly managed ecosystem subject to frequent fertilization, mowing, irrigation, and application of pesticides. Turf management practices may create a perturbed environment for ammonia oxidizers, a key microbial group responsible for nitrification. To elucidate the long-term effects of turf management on these bacteria, we assessed the composition of betaproteobacterial ammonia oxidizers in a chronosequence of turfgrass systems (i.e., 1, 6, 23, and 95 years old) and the adjacent native pines by using both 16S rRNA and amoA gene fragments specific to ammonia oxidizers. Based on the Shannon-Wiener diversity index of denaturing gradient gel electrophoresis patterns and the rarefaction curves of amoA clones, turf management did not change the relative diversity and richness of ammonia oxidizers in turf soils as compared to native pine soils. Ammonia oxidizers in turfgrass systems comprised a suite of phylogenetic clusters common to other terrestrial ecosystems. Nitrosospira clusters 0, 2, 3, and 4; Nitrosospira sp. Nsp65-like sequences; and Nitrosomonas clusters 6 and 7 were detected in the turfgrass chronosequence with Nitrosospira clusters 3 and 4 being dominant. However, both turf age and land change (pine to turf) effected minor changes in ammonia oxidizer composition. Nitrosospira cluster 0 was observed only in older turfgrass systems (i.e., 23 and 95 years old); fine-scale differences within Nitrosospira cluster 3 were seen between native pines and turf. Further investigations are needed to elucidate the ecological implications of the compositional differences.}, number={1}, journal={MICROBIAL ECOLOGY}, author={Dell, Emily A. and Bowman, Daniel and Rufty, Thomas and Shi, Wei}, year={2008}, month={Jul}, pages={178–190} }
 @article{bowman_cramer_devitt_2006, title={Effect of Salinity and Nitrogen Status on Nitrogen Uptake by Tall Fescue Turf}, volume={29}, ISSN={0190-4167 1532-4087}, url={http://dx.doi.org/10.1080/01904160600837584}, DOI={10.1080/01904160600837584}, abstractNote={ABSTRACT Nitrogen (N) absorption is inhibited by root zone salinity, which could result in increased NO3 leaching. Conversely, N absorption is enhanced by moderate N deficiency. Because turfgrasses are grown under N-limiting conditions, it is important to understand the interactive effects of salinity and N deficiency on N uptake. This study examined the effect of N status (replete versus deficient) and salinity on N (15NO3 and 15 NH4) uptake and partitioning by tall fescue (Festuca arundinacea Schreb.). Two cultivars (‘Monarch’ and ‘Finelawn I’) were grown in nutrient solution culture. Treatments included N level (100% or 25% of maximum N demand) and salinity (0, 40, 80, and 120 meq L−1) in a factorial arrangement. Absorption of NO3 and NH4 was greater in low-N than in high-N cultures, but was reduced by salinity under both N treatments. Salinity reduced partitioning of absorbed N to leaves and increased retention in roots. These results suggest that turfgrass managers should consider irrigation water quality when developing their fertilizer program.}, number={8}, journal={Journal of Plant Nutrition}, publisher={Informa UK Limited}, author={Bowman, Daniel C. and Cramer, Grant R. and Devitt, Dale A.}, year={2006}, month={Aug}, pages={1481–1490} }
 @article{bowman_cramer_devitt_2006, title={Effect of nitrogen status on salinity tolerance of tall fescue turf}, volume={29}, ISSN={["0190-4167"]}, DOI={10.1080/01904160600837600}, abstractNote={ABSTRACT Turfgrass salinity tolerance is usually studied under conditions of non-limiting nutrition, even though most turfgrasses are managed with growth-limiting levels of nitrogen (N). This study examined the effect of N status (replete versus deficient) on salinity tolerance in tall fescue (Festuca arundinacea Schreb.). Additionally, the interactive effects of N status and salinity on tissue ion concentrations were determined. Two cultivars (‘Monarch’ and ‘Finelawn I’) were grown in nutrient solution culture. Treatments included N level (100% or 25% of maximum N demand) and salinity (0, 40, 80, 120 meq L−1). Salinity reduced leaf growth under high-N conditions, but much less so under low-N conditions. Concentrations of potassium (K), sodium (Na), and chloride (Cl) in the leaf sap were significantly higher in low-N than in high-N plants, indicating that increased salinity tolerance in low-N turf was not due to ion exclusion. These results suggest that efforts to screen turfgrasses for salt tolerance should be conducted using realistic N-fertility levels.}, number={8}, journal={JOURNAL OF PLANT NUTRITION}, author={Bowman, Daniel C. and Cramer, Grant R. and Devitt, Dale A.}, year={2006}, month={Aug}, pages={1491–1497} }
 @article{shi_dell_bowman_iyyemperumal_2006, title={Soil enzyme activities and organic matter composition in a turfgrass chronosequence}, volume={288}, ISSN={["1573-5036"]}, DOI={10.1007/s11104-006-9116-1}, number={1-2}, journal={PLANT AND SOIL}, author={Shi, Wei and Dell, Emily and Bowman, Daniel and Iyyemperumal, Kannan}, year={2006}, month={Oct}, pages={285–296} }
 @article{shi_muruganandam_bowman_2006, title={Soil microbial biomass and nitrogen dynamics in a turfgrass chronosequence: A short-term response to turfgrass clipping addition}, volume={38}, ISSN={["0038-0717"]}, DOI={10.1016/j.soilbio.2006.01.005}, abstractNote={A mechanistic understanding of soil microbial biomass and N dynamics following turfgrass clipping addition is central to understanding turfgrass ecology. New leaves represent a strong sink for soil and fertilizer N, and when mowed, a significant addition to soil organic N. Understanding the mineralization dynamics of clipping N should help in developing strategies to minimize N losses via leaching and denitrification. We characterized soil microbial biomass and N mineralization and immobilization turnover in response to clipping addition in a turfgrass chronosequence (i.e. 3, 8, 25, and 97 yr old) and the adjacent native pines. Our objectives were (1) to evaluate the impacts of indigenous soil and microbial attributes associated with turf age and land use on the early phase decomposition of turfgrass clippings and (2) to estimate mineralization dynamics of turfgrass clippings and subsequent effects on N mineralization of indigenous soils. We conducted a 28-d laboratory incubation to determine short-term dynamics of soil microbial biomass, C decomposition, N mineralization and nitrification after soil incorporation of turfgrass clippings. Gross rates of N mineralization and immobilization were estimated with 15N using a numerical model, FLAUZ. Turfgrass clippings decomposed rapidly; decomposition and mineralization equivalent to 20–30% of clipping C and N, respectively, occurred during the incubation. Turfgrass age had little effect on decomposition and net N mineralization. However, the response of potential nitrification to clipping addition was age dependent. In young turfgrass systems having low rates, potential nitrification increased significantly with clipping addition. In contrast, old turfgrass systems having high initial rates of potential nitrification were unaffected by clipping addition. Isotope 15N modeling showed that gross N mineralization following clipping addition was not affected by turf age but differed between turfgrass and the adjacent native pines. The flush of mineralized N following clipping addition was derived predominantly from the clippings rather than soil organic N. Our data indicate that the response of soil microbial biomass and N mineralization and immobilization to clipping addition was essentially independent of indigenous soil and microbial attributes. Further, increases in microbial biomass and activity following clipping addition did not stimulate the mineralization of indigenous soil organic N.}, number={8}, journal={SOIL BIOLOGY & BIOCHEMISTRY}, author={Shi, Wei and Muruganandam, Subathra and Bowman, Daniel}, year={2006}, month={Aug}, pages={2032–2042} }
 @article{yao_bowman_shi_2006, title={Soil microbial community structure and diversity in a turfgrass chronosequence: Land-use change versus turfgrass management}, volume={34}, ISSN={["1873-0272"]}, DOI={10.1016/j.apsoil.2006.01.009}, abstractNote={A diverse soil microbial community is an important measure of sustainable land use. Turfgrasses are usually managed as a monostand, which may result in reduced soil microbial diversity. However, there is little information on the structure and diversity of soil microorganisms in managed turfgrass systems. We examined the soil microbial community in a turfgrass chronosequence (i.e., 1, 6, 23 and 95 years), established from native pines, to address (1) the degree to which microbial diversity is achieved and maintained in turfgrass soils and (2) the relative importance of turfgrass management versus land-use change (i.e., native pines to turfgrass) in structuring the soil microbial community. Soil microbial communities were fingerprinted using phospholipid fatty acid (PLFA) composition, and also by the pattern of sole C source utilization (i.e., community-level physiological profiles, CLPP). The relative diversities of soil microbial communities as a function of land use and turfgrass ages were compared using the Shannon index. Multivariate analysis was used to detail variations in soil microbial communities. Despite the differences in land use and turfgrass age, microbial biodiversity was generally similar for the various soils, with the exception that diversity was lower in soils taken from 5 to 15 cm depth of the two youngest turfgrass systems. This reduction was correlated with low soil C, and suggests that soil organic matter (OM) is a primary determinant of microbial community diversity. Both CLPP- and PLFA-based principal component analyses (PCA) revealed distinct groupings of soil microbial communities based on land use but not on turfgrass age. There was a preferential use of phenolic compounds and carboxylic acids by the microbial community in native pine soils, whereas carbohydrates were the preferred C source for microbial communities in turfgrass soils. This difference in catabolic function was mirrored by a compositional change of phospholipid fatty acids. Cluster analysis of community structure indicated that microbial communities in older turfgrass systems (23 and 95 years old) diverged from younger systems (1 and 6 years old), implying some effect of management on composition and structure of the soil microbial community. Our study concludes that a diverse soil microbial community was achieved and maintained in turfgrass systems, and that shifts in soil microbial community structure were attributed primarily to the change of land use rather than the length of turfgrass management.}, number={2-3}, journal={APPLIED SOIL ECOLOGY}, author={Yao, Huaiying and Bowman, Daniel and Shi, Wei}, year={2006}, month={Dec}, pages={209–218} }
 @article{bowman_devitt_miller_2006, title={The effect of moderate salinity on nitrate leaching from bermudagrass turf: A lysimeter study}, volume={175}, ISSN={["1573-2932"]}, DOI={10.1007/s11270-006-9110-5}, number={1-4}, journal={WATER AIR AND SOIL POLLUTION}, author={Bowman, D. C. and Devitt, Dale A. and Miller, W. Wally}, year={2006}, month={Sep}, pages={49–60} }
 @article{bowman_devitt_miller_2007, title={The effect of moderate salinity on nitrate leaching from bermudagrass turf: A lysimeter study (vol 175, pg 49, 2006)}, volume={182}, ISSN={["0049-6979"]}, DOI={10.1007/s11270-006-9315-7}, abstractNote={A column lysimeter study was conducted under greenhouse conditions to determine the impact of moderately saline irrigation water on NO3 leaching from turfgrass. Bermudagrass (Cynodon dactylon L. ‘NuMex Sahara’) was fertilized at three N levels (25, 50 and 75 kg NH4NO3-N ha−1 month−1) and irrigated with saline water (0, 3.0 and 6.0 dS m−1) in a factorial arrangement. Leachate was analyzed for salinity and NO3, and clippings were collected and analyzed for total N. Nitrate leaching was not affected by either N level or salinity. Nitrate concentrations in the leachate were low, averaging approximately 0.3 mg N L−1; less than 1% of the applied N leached. Longer-term N allocation to leaf growth accounted for up to 98% of applied N, whereas short-term allocation, determined using 15N, ranged from 46–67%. Salinity had no affect on clipping yield, the biomass of root and verdure, or root distribution. These data indicate the potential for moderately saline irrigation water to be used on bermudagrass turf without increasing NO3 contamination of groundwater, as long as leaching is adequate to prevent rootzone salinity reaching damaging levels.}, number={1-4}, journal={WATER AIR AND SOIL POLLUTION}, author={Bowman, D. C. and Devitt, Dale A. and Miller, W. Wally}, year={2007}, month={Jun}, pages={417–419} }
 @article{shi_yao_bowman_2006, title={Soil microbial biomass, activity and nitrogen transformations in a turfgrass chronosequence}, volume={38}, ISSN={["0038-0717"]}, DOI={10.1016/j.soilbio.2005.05.008}, abstractNote={Understanding the chronological changes in soil microbial properties of turfgrass ecosystems is important from both the ecological and management perspectives. We examined soil microbial biomass, activity and N transformations in a chronosequence of turfgrass systems (i.e. 1, 6, 23 and 95 yr golf courses) and assessed soil microbial properties in turfgrass systems against those in adjacent native pines. We observed age-associated changes in soil microbial biomass, CO2 respiration, net and gross N mineralization, and nitrification potential. Changes were more evident in soil samples collected from 0 to 5 cm than the 5 to 15 cm soil depth. While microbial biomass, activity and N transformations per unit soil weight were similar between the youngest turfgrass system and the adjacent native pines, microbial biomass C and N were approximately six times greater in the oldest turfgrass system compared to the adjacent native pines. Potential C and N mineralization also increased with turfgrass age and were three to four times greater in the oldest vs. the youngest turfgrass system. However, microbial biomass and potential mineralization per unit soil C or N decreased with turfgrass age. These reductions were accompanied by increases in microbial C and N use efficiency, as indicated by the significant reduction in microbial C quotient (qCO2) and N quotient (qN) in older turfgrass systems. Independent of turfgrass age, microbial biomass N turnover was rapid, averaging approximately 3 weeks. Similarly, net N mineralization was ∼12% of gross mineralization regardless of turfgrass age. Our results indicate that soil microbial properties are not negatively affected by long-term management practices in turfgrass systems. A tight coupling between N mineralization and immobilization could be sustained in mature turfgrass systems due to its increased microbial C and N use efficiency.}, number={2}, journal={SOIL BIOLOGY & BIOCHEMISTRY}, author={Shi, W and Yao, HY and Bowman, D}, year={2006}, month={Feb}, pages={311–319} }
 @article{uriarte_shew_bowman_2004, title={Effect of soluble silica on brown patch and dollar spot of creeping bentgrass}, volume={27}, ISSN={["1532-4087"]}, DOI={10.1081/PLN-120027657}, abstractNote={Abstract Disease pressure on cool season turfgrasses is very high in the transition zone due to the heat and humidity of prolonged summers. Creeping bentgrass (Agrostis stolonifera L.) is susceptible to both brown patch (Rhizoctonia solani Kuhn) and dollar spot (Sclerotinia homoeocarpa F.T. Bennett) fungi. The objective of this study was to assess the potential of soluble silica for reducing the severity or incidence of disease on creeping bentgrass. Two mature stands of creeping bentgrass, maintained as putting greens, were used. Both greens were constructed to USGA specifications and planted with either “Penncross” or “Cato” and “Crenshaw” blend creeping bentgrass. Plots were treated biweekly with silica at rates of 0, 25, and 50 kg ha−1. Turf quality was unaffected by silica application. Differences in disease incidence between the silica treatments and the control were observed in 1995 but not in 1996. There was no effect of treatment on tissue Si, suggesting that creeping bentgrass may be a Si excluder. Based on these results, silica may provide some degree of protection from dollar spot and brown patch. However, the level of control is unlikely to satisfy expectations for putting green turf quality.}, number={2}, journal={JOURNAL OF PLANT NUTRITION}, author={Uriarte, RF and Shew, HD and Bowman, DC}, year={2004}, pages={325–339} }
 @article{fagerness_bowman_yelverton_rufty_2004, title={Nitrogen use in Tifway bermudagrass, as affected by trinexapac-ethyl}, volume={44}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2004.5950}, abstractNote={Nutrient movement from turfgrass systems into surface and ground water is a public concern. Data indicate that actively growing turf rapidly immobilizes applied N, thus restricting nutrient movement. It is possible, however, that growth suppression with plant growth regulators (PGRs) could reduce N demand and thus N uptake, resulting in greater leaching losses. An experiment was conducted with column lysimeters to investigate the effects of trinexapac‐ethyl (TE) on nitrate leaching and N‐use efficiency in Tifway bermudagrass (Cynodon dactylon × C. transvaalensis). The experiment was conducted in a growth chamber with day/night temperature set at 29/24°C and a 12‐h photoperiod. Trinexapac‐ethyl was applied twice at 4‐wk intervals at 0.11 kg a.i. ha−1 Ammonium nitrate (AN) was applied at 50 kg N ha−1 2 wk after each TE application, and again 6 wk after the second TE application. Separate sets of columns received 15N‐labeled AN for the first two applications. Irrigation was scheduled to provide a leaching fraction of ≈50%; leachate was collected after each irrigation and analyzed for nitrate and ammonium. Cumulative nitrate leaching was unaffected by TE after the first two N applications, but was reduced ≈60% by TE following the third N application. Trinexapac‐ethyl reduced 15N allocation to clippings by ≈25% and increased 15N allocation to roots and rhizomes; total recovery of applied 15N in tissues was ≈65%. Results demonstrate chemical growth suppression with TE does not reduce N uptake or increase nitrate leaching from bermudagrass.}, number={2}, journal={CROP SCIENCE}, author={Fagerness, MJ and Bowman, DC and Yelverton, FH and Rufty, TW}, year={2004}, pages={595–599} }
 @article{bigelow_bowman_cassel_2004, title={Physical properties of three sand size classes amended with inorganic materials or sphagnum peat moss for putting green rootzones}, volume={44}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2004.0900}, abstractNote={Modern putting green rootzones are typically constructed using sands to avoid compaction and facilitate rapid drainage. Sands are often amended with organic matter (OM) such as sphagnum peat moss (SP) to increase moisture holding capacity. However, OM decomposition into finely divided material may negatively affect long-term soil physical properties. Inorganic amendments (IAs) having high water retention may be more suitable because of their resistance to biodegradation. A laboratory study determined the physical properties [bulk density, saturated hydraulic conductivity (Ksat), water retention, and pore size distribution] of three USDA sand size classes (fine, medium, and coarse) with and without amendment. Amendments used were calcined clay, vitrified clay, extruded diatomaceous earth, a processed zeolite, and SP. Amendments were tested at two incorporation rates (10 and 20% v/v), and in situ in 30-cm-deep rootzones at two incorporation depths (15 and 30 cm). Bulk density decreased, total porosity increased, and Ksat declined with amendment rate, but varied considerably depending on amendment, sand size, and incorporation depth. The Ksat was high for all mixtures, averaging 250 cm h−1, probably because of the very uniform sands. On the basis of standard pressure plate methods, IAs increased total water holding capacity (WHC) of all three sands but did not increase available water. However, a unique bioassay for available water indicated that porous IAs may contain appreciably more available water than measured by the pressure plate technique. Although the IAs significantly altered the physical properties of the three sands, they were not as effective as SP at improving water retention in coarse-textured, drought-prone sands.}, number={3}, journal={CROP SCIENCE}, author={Bigelow, CA and Bowman, DC and Cassel, DK}, year={2004}, pages={900–907} }
 @article{bowman_2003, title={Daily vs. periodic nitrogen addition affects growth and tissue nitrogen in perennial ryegrass turf}, volume={43}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2003.0631}, abstractNote={Nitrogen is typically supplied to turfgrasses either in large episodic pulses of readily available fertilizer N, or in relatively small, constant fluxes from mineralization, slow release fertilizers, or fertigation. There is little information on the comparative physiology and productivity resulting from each strategy. A greenhouse study was conducted to determine turfgrass productivity and N partitioning as a function of daily (near-constant) vs. intermittent N supply. Perennial ryegrass (Lolium perenne L.) was grown in solution culture and fertilized daily with KNO3 at rates ranging from 0.56 to 11.1 kg N ha−1 d−1 (daily N), or in pulses delivered every 8, 16, or 32 d to supply 50 kg N ha−1 mo−1 (intermittent N). Leaf growth rate, reduced N, and NO3–N content were relatively stable under daily N, with steady state values for each parameter strongly affected by N rate. Intermittent N caused fluctuations in growth and tissue N coincident with application. Nitrogen absorption was rapid and complete for all but the highest rate of daily N. Nitrogen supplied intermittently was absorbed quantitatively across a period of 8 to 36 h. Allocation to new leaf growth accounted for 88 to 119% of the absorbed N. Shoot biomass increased, whereas root biomass and length decreased with increasing daily N rate. The results indicate that while daily N supply produces relatively constant growth and stable tissue N pools, there is little benefit to long-term productivity and N use efficiency when compared with intermittent supply of N.}, number={2}, journal={CROP SCIENCE}, author={Bowman, DC}, year={2003}, pages={631–638} }
 @article{lee_bowman_cassel_peacock_rufty_2003, title={Soil inorganic nitrogen under fertilized bermudagrass turf}, volume={43}, DOI={10.2135/cropsci2003.2470}, abstractNote={Managed turfgrass acreage in the southeastern USA is steadily increasing. There is public concern that fertilization of turfgrass systems, particularly additions of N on golf courses, might be adversely affecting groundwater quality due to nitrate leaching. This study was conducted to measure soil nitrate levels in situ under continuously managed bermudagrass (Cynodon spp.) and to evaluate influences from fertilization and mineralization. Two experimental sites were established on 50‐ and 75‐yr‐old golf course fairways in the Neuse and Cape Fear River basins in eastern North Carolina. Soil sampling was done seasonally. Results indicate that nitrate‐N levels were consistently low (1 to 4 mg kg−1 soil) and similar to adjacent natural areas throughout the 120‐cm sampling depths during the 2‐yr experiment at both sites. Levels were relatively uniform with depth and across several landscape positions. The soil nitrate levels under fertilized fairways were similar to those in adjacent nonfertilized natural areas, indicating minimal influence from turf management practices. From laboratory mineralization studies and soil temperature data, it was estimated that 60 to 154 kg N ha−1 would be released from organic N pools during the bermudagrass growing season (May to October). Because of similar temperature responses, it appeared that N release from mineralization would be synchronized with bermudagrass growth. Substantial bermudagrass growth in nonfertilized plots provided direct evidence that mineralization was a significant contributor to turf nutrition. There was no evidence that N fertilization or the ecology of the bermudagrass system posed inherent risks to water quality and the environment.}, number={1}, journal={Crop Science}, author={Lee, D. J. and Bowman, D. C. and Cassel, D. K. and Peacock, C. H. and Rufty, T. W.}, year={2003}, pages={247–257} }
 @article{bigelow_bowman_wollum_2002, title={Characterization of soil microbial population dynamics in newly constructed sand-based rootzones}, volume={42}, DOI={10.2135/cropsci2002.1611}, abstractNote={Modern sand-based golf course putting greens are constructed for optimum soil physical properties. However, since they are sand based and synthetically prepared, it is often perceived that they support a less numerous and diverse microbial population than comparable native soils. This field study was conducted to monitor the microbial properties of five newly constructed sand-based rootzone mixtures planted to creeping bentgrass (Agrostis stolonifera var. palustris Huds. Farw.) during the first 2 yr of turfgrass establishment. Bacteria, fungi, actinomycetes, and aerobic spore forming (Bacillus spp.) populations were determined on selective media. Nitrifiers and denitrifiers were estimated by a most probable number (MPN) technique. Within the first 6 mo after seeding, bacteria exceeded 10 8 cfu g -1 dry soil, similar to levels recorded in a mature sand-based putting green. Bacteria were most numerous followed by actinomycetes, fungi, and Bacillus spp., respectively. Temporal changes in microbial populations were observed only in year one. The nitrogen transforming populations were numerically smaller (<10 4 cfu g -1 dry soil) than total bacteria but followed a similar temporal trend. Rootzone amendments had minimal effects on microbial properties but environmental factors and an actively growing turfgrass root system may have a greater influence on microbial activity.}, number={5}, journal={Crop Science}, author={Bigelow, C. A. and Bowman, D. C. and Wollum, A. G.}, year={2002}, pages={1611–1614} }
 @article{bowman_cherney_rufty_2002, title={Fate and transport of nitrogen applied to six warm-season turfgrasses}, volume={42}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2002.0833}, abstractNote={A greenhouse study compared six warm season turfgrasses {common bermudagrass [Cynodon dactylon (L.) Pers.], ‘Tifway’ hybrid bermudagrass (C. dactylon × transvaalensis), centipedegrass (Eremochloa ophiuroides (Munro) Hack.), ‘Raleigh’ St. Augustinegrass [Stenotaphrum secundatum (Walter) Kuntze], ‘Meyer’ zoysiagrass (Zoysia japonica Steud.), and ‘Emerald’ zoysiagrass (Z. japonica × tenuifolia)] for NO3-N leaching and N use efficiency. Sod was established in sand-filled columns and managed under worst-case conditions to promote nitrate leaching. Ammonium nitrate was applied at 50 kg N ha−1 on seven dates, with the final application labeled with 15N. Leachate samples were collected and analyzed for NO3-N and NH4-N and clippings were analyzed for total N. Leaching losses were high following the first N application, ranging from 48 to 100% of the NO3-N and 4 to 16% of the NH4-N applied. Nitrate loss from subsequent applications was reduced substantially, while NH4 leaching was essentially eliminated. There were significant differences among species for leachate NO3-N concentration and cumulative N leached, with St. Augustinegrass being the most effective and Meyer zoysiagrass the least effective at minimizing NO3 leaching. Nitrogen recovery by the turf ranged from 63% for Meyer zoysiagrass to 84% for hybrid bermudagrass. Root length density (RLD) varied significantly among species at depths >30 cm, and was negatively correlated with NO3 leaching loss. These results document differences between the warm season turfgrasses for NO3 leaching potential, possibly related to root distribution, and emphasize that species selection is an important factor in minimizing environmental impacts from turfgrass management.}, number={3}, journal={CROP SCIENCE}, author={Bowman, DC and Cherney, CT and Rufty, TW}, year={2002}, pages={833–841} }
 @article{bigelow_bowman_cassel_rufty_2001, title={Creeping bentgrass response to inorganic soil amendments and mechanically induced subsurface drainage and aeration}, volume={41}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2001.413797x}, abstractNote={Creeping bentgrass (Agrostis stolonifera var. palustris Huds. Farw.) golf greens often decline under the hot, humid summer conditions of the southeastern USA. Factors associated with this decline may be poor soil aeration, excessive soil wetness, high temperatures, and turfgrass diseases. A field study evaluated a mechanical forced air system for its ability to modify the soil water content and oxygen (O2) status of newly constructed sand‐based rootzones, and its effects on turfgrass quality (TQ) and seasonal bentgrass rooting. Three drainage situations were studied: gravity drainage (control treatment) and gravity drainage supplemented by two mechanically induced drainage treatments, water evacuation (WE) or WE followed by air‐injection (AI). In addition, the effects of peat moss and several inorganic soil amendments on bentgrass establishment and growth were studied. Compared with gravity drainage, WE significantly decreased water contents (0.01–0.05 m3 m−3) averaged across the 0‐ to 27‐cm depth, with the greatest change occurring near the bottom of the rooting media. Seasonal fluctuations in soil O2 and CO2 concentrations were observed, but O2 remained high, 0.19 m3 m−3, and CO2 was low, <0.01 m3 m−3, regardless of drainage treatment. Drainage treatments had no effect on TQ or root mass density (RMD). However, both TQ and RMD increased from 1998 to 1999, possibly becaue of greater turfgrass density. Amendments had significant effects on establishment and TQ in the following order: peat moss > Ecolite = Profile > Greenschoice ≥ unamended sand. This response was probably due to improved water and nutrient retention of the amended rootzones. Although the forced air–vacuum technology provided little benefit in these newly constructed greens, it may be useful on mature putting greens that suffer from poor soil aeration or drainage.}, number={3}, journal={CROP SCIENCE}, author={Bigelow, CA and Bowman, DC and Cassel, DK and Rufty, TW}, year={2001}, pages={797–805} }
 @article{bigelow_bowman_cassel_2001, title={Nitrogen leaching in sand-based rootzones amended with inorganic soil amendments and sphagnum peat}, volume={126}, number={1}, journal={Journal of the American Society for Horticultural Science}, author={Bigelow, C. A. and Bowman, D. C. and Cassel, D. K.}, year={2001}, pages={151–156} }
 @misc{mitchell_bowman_penttila_sharapov_2001, title={Parity violation in compound nuclei: experimental methods and recent results}, volume={354}, ISSN={["1873-6270"]}, DOI={10.1016/S0370-1573(01)00016-3}, abstractNote={The TRIPLE Collaboration studies of space-parity symmetry in the compound nucleus show numerous examples of parity violation in Br, Rh, Pd, Ag, Cd, In, Sn, Sb, I, Cs, Xe, La, U, and Th. The longitudinal cross section asymmetries have measured values in the range of 10−3–10−1 for neutron energies from several eV up to 300–2000eV, depending on the target. The high density of states leads to enhancement of the parity violation by factors as large as 106 relative to parity violation in pp scattering. The high degree of complexity of the levels permits the use of statistical methods for determination of the root mean square weak matrix element M for each nucleus. This report is focused on the experimental results of the TRIPLE Collaboration studies. Parity violation has been observed in 75 resonances of 18 nuclides. The experimental data and analysis are presented for each nuclide studied. A nonstatistical anomaly (the sign correlation effect) was observed in thorium. Statistical analysis techniques were developed and successfully applied to determine the rms weak matrix elements and the weak spreading widths Γw. The value of Γw obtained from our analysis is about 1.8×10−7eV, which is in qualitative agreement with theoretical expectations. The individual weak spreading widths are consistent with a constant or slowly varying mass dependence and there is evidence for local fluctuations.}, number={3}, journal={PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS}, author={Mitchell, GE and Bowman, JD and Penttila, SI and Sharapov, EI}, year={2001}, month={Nov}, pages={157–241} }
 @article{bruneau_bigelow_cooper_bowman_2001, title={Performance of creeping bentgrass cultivars maintained at two mowing heights and under two fungicide regimes in North Carolina}, volume={9}, journal={International Turfgrass Society Research Journal}, author={Bruneau, A. H. and Bigelow, C. A. and Cooper, R. J. and Bowman, D. C.}, year={2001}, pages={835} }
 @article{lee_wollum_bowman_peacock_rufty_2001, title={Temperature effects on nitrogen mineralization in bermudagrass turf}, volume={9}, journal={International Turfgrass Society Research Journal}, author={Lee, D. J. and Wollum, A. G. and Bowman, D. C. and Peacock, C. H. and Rufty, T. W., Jr.}, year={2001}, pages={394} }
 @article{bigelow_bowman_cassel_2001, title={Water retention of sand-based putting green mixtures as affected by the presence of gravel sub-layers}, volume={9}, journal={International Turfgrass Society Research Journal}, author={Bigelow, C. A. and Bowman, D. C. and Cassel, D. K.}, year={2001}, pages={479} }
 @article{weisz_bowman_1999, title={Influence of tillage system on soft red winter wheat cultivar selection}, volume={12}, ISSN={["0890-8524"]}, DOI={10.2134/jpa1999.0415}, abstractNote={Soft red winter wheat (Triticum aestivum L.) producers in the southeastern USA are adopting no-till production practices. Official wheat cultivar testing programs, however, are conducted in conventional-till. The objective of this research was to determine whether soft red winter wheat cultivars perform differently across tillage systems, indicating the need for no-till cultivar testing programs. Twelve winter wheat cultivars commonly produced in the southeastern USA were tested in a split-plot design with tillage system as the main effect. The test was located in the North Carolina Piedmont and Coastal Plain in 1996 and 1997. In the Piedmont the soil type was Hiwassee clay loam (fine, kaolinitic, thermic Typic Rhodudults), and in the Coastal Plain the soil was Goldsboro sandy loam (fineloamy, siliceous, subactive, Aquic Paleudults). Plant density after emergence, head density at harvest, kernel weight, grain yield, and test-weight were determined and compared across cultivars and tillage systems. For each of these variables, environment and cultivar effects were significant (P ≤ 0.05). Tillage system had a significant effect only on plant density with average no-till stands being 8.3 % lower than those in the conventional-till system. Relative cultivar performance, or rank, did not change across tillage systems for any of these variables. Consequently, soft red winter wheat cultivars that perform well in conventional-till will probably be the best adapted for no-till production. Separate cultivar trials are not required for the two tillage systems.}, number={3}, journal={JOURNAL OF PRODUCTION AGRICULTURE}, author={Weisz, R and Bowman, DT}, year={1999}, pages={415–418} }
 @article{bigelow_cassel_bowman_1999, title={Soil amendments: reduce nitrate leaching}, volume={8}, number={9}, journal={Turf Grass Trends}, author={Bigelow, C. A. and Cassel, D. K. and Bowman, D. C.}, year={1999}, pages={11} }
 @inbook{bowman_devitt_miller_2000, title={The Effects of salinity on nitrate leaching from tall fescue turfgrass}, volume={743}, DOI={10.1021/bk-2000-0743.ch010}, abstractNote={A column study was conducted to determine the impact of saline irrigation water on N03 leaching from turfgrass. Tall fescue turf was grown in columns filled with sand and outfitted with a vacuum drainage system. Treatments consisted of three N levels (25, 50 and 75 kg NH4NO3 -N ha-1 month-1) and three irrigation salinity levels (0, 1.5 and 3 dS m-1) in a 3 X 3 factorial arrangement. Irrigation was scheduled to provide a 30% leaching fraction. Leachate was collected quantitatively after every irrigation and analyzed for salts and NO3-N. Clippings were collected and analyzed for total N. Nitrate concentrations in the leachate were very low, averaging approximately 1.0 mg N L-1. Clipping yield and N content were unaffected by salinity, while root mass was increased. These data indicate that moderate levels of rootzone salinity do not increase NO3 leaching, nor do they impair growth or N absorption. This suggests}, number={2000}, booktitle={Fate and management of turfgrass chemicals}, publisher={Washington, DC: American Chemical Society}, author={Bowman, D. C. and Devitt, D. A. and Miller, W. W.}, editor={J. M. Clark and Kenna, M. P.Editors}, year={2000}, pages={164–178} }
 @article{bowman_devitt_huff_miller_1998, title={Comparative evapotranspiration of seventeen buffalograss (Buchloe dactyloides (Nutt.) Engelm.) genotypes.}, volume={2}, number={4}, journal={Journal of Turfgrass Management}, author={Bowman, D. C. and Devitt, D. A. and Huff, D. R. and Miller, W. W.}, year={1998}, pages={1–10} }
 @article{liu_cooper_bowman_1998, title={Humic acid application affects photosynthesis, root development, and nutrient content of creeping bentgrass}, volume={33}, number={6}, journal={HortScience}, author={Liu, C. H. and Cooper, R. J. and Bowman, D. C.}, year={1998}, pages={1023–1025} }
 @article{bowman_devitt_engelke_rufty_1998, title={Root architecture affects nitrate leaching from bentgrass turf}, volume={38}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1998.0011183X003800060036x}, abstractNote={Understanding the determinants of nitrate leaching should improve nitrogen uptake efficiency and reduce ground water contamination. This column lysimeter study examined the effect of root architecture on NO3 leaching from two genotypes of creeping bentgrass (Agrostis palustris Huds.) differing in rooting characteristics. Ammonium nitrate was applied (50 kg N ha−1) and the columns were irrigated with 1, 2 or 3 cm day−1 (Exp. 1) or irrigation was delayed 1, 3 or 5 d (Exp. 2). In Exp. 1, leachate NO3 concentrations and total N leached from the shallow‐rooted (SR) genotype were approximately twice those from the deep‐rooted (DR) genotype. An average of 38 and 18% of the applied N leached from the SR and DR genotypes, respectively. Cumulative leaching losses increased with irrigation depth. In Exp. 2, NO3 leaching was reduced 90% or more by increasing the time period for immobilization from 1 to 5 d. Recovery of applied 15N in the tissue averaged 87% after 2 mo. Absorption of NO3 and NH4 was measured in nutrient solution culture. The SR genotype had significantly higher uptake rates than DR for both forms of N, expressed on a root weight basis. Collectively these data indicate that a deep‐rooted turfgrass absorbs N more efficiently than a shallowrooted turf, reducing the concentration and total amount of NO3 leached. The effect is apparently not due to differences in N uptake, but rather to rooting patterns. Environmental conditions and management practices that affect rooting depth and density may thus affect N nutrition and NO3 leaching.}, number={6}, journal={CROP SCIENCE}, author={Bowman, DC and Devitt, DA and Engelke, MC and Rufty, TW}, year={1998}, pages={1633–1639} }