SWAT model Instances for "Quantifying nitrate leaching to groundwater from a corn-peanut rotation under a variety of irrigation and nutrient management practices in the Suwannee River Basin, Florida"

The Soil and Water Assessment Tool (SWAT) was used to simulate crop yields and nitrate leaching for corn-peanut rotations under a variety of nutrient and irrigation management practices in the Suwannee River Basin (Florida), where groundwater feeds springs that are protected by a federally mandated nutrient criteria of 0.35 mg/L Nitrate-Nitrogen (NO3-N). Data from a field experiment of nine irrigation and nitrogen (N) management treatments were used to calibrate SWAT, with good to excellent results (Nash Sutcliffe Efficiencies from 0.72 to 0.97 for soil moisture, 0.85–0.96 for crop yield, 0.48–0.96 for crop N uptake, and 0.15–0.82 for soil nitrate). The calibrated model was then used to quantify differences in crop yields, irrigation applied and nitrate leaching among practices over a range of historical weather. Soil moisture sensor-based irrigation with 246 kg N/ha for corn and 0 kg N/ha for peanut showed no statistical difference in yields compared to common practices in the region (calendar-based irrigation, fertilization of 336 kg N/ha corn and 17 kg N/ha peanut), while reducing N leaching by 40% and irrigation applied by 45% (reductions of ~70 kg N/ha/ yr and ~300 mm/year, respectively). Planting a rye cover crop during the fallow season reduced leaching by an additional ~50 N/ha/yr for all treatments. These results show the potential for widespread adoption of nutrient and water conservation practices to achieve the reductions in NO3-N load needed to meet environmental and regulatory goals without impacting crop yields. This work is published in Rath S. , M. Zamora-Re, W. Graham, M. Dukes, and D. Kaplan, Quantifying nitrate leaching to groundwater from a corn-peanut rotation under a variety of irrigation and nutrient management practices in the Suwannee River Basin, Florida, Agricultural Water Management. https://doi.org/10.1016/j.agwat.2020.106634 , 2021. Experimental data used to calibrate and validate the model is archived at Zamora-Re, M., J. Merrick, M. Dukes (2021). Floridan Aquifer Collaborative Engagement for Sustainability (FACETS) – Field trial data from Live Oak, Florida. Ag Data Commons. https://doi.org/10.15482/USDA.ADC/1521079.本研究以佛罗里达州苏旺尼河流域为研究区域，该流域地下水补给多处受联邦法定标准保护的泉眼，其管控要求为硝酸盐氮（Nitrate-Nitrogen，NO3-N）浓度不超过0.35 mg/L。研究采用土壤与水评估工具（Soil and Water Assessment Tool，SWAT），模拟了不同养分与灌溉管理措施下玉米-花生轮作系统的作物产量与硝酸盐淋失量。研究基于9种灌溉与氮（N）管理措施的田间试验数据对SWAT模型进行率定，率定结果良好至优秀：土壤含水率的纳什-舒特克利夫效率（Nash Sutcliffe Efficiencies）介于0.72~0.97之间，作物产量为0.85~0.96，作物吸氮量为0.48~0.96，土壤硝酸盐含量为0.15~0.82。经率定后的模型被用于量化历史气象条件下不同管理措施间的作物产量、灌溉用水量与硝酸盐淋失量的差异。结果显示，采用基于土壤湿度传感器的灌溉方案，且玉米施氮量为246 kg/ha、花生施氮量为0 kg/ha时，与当地常规措施（基于日历的灌溉方式，玉米施氮336 kg/ha、花生施氮17 kg/ha）相比，作物产量无统计学差异，但可将氮淋失量降低40%、灌溉用水量减少45%（分别约合每年70 kg N/ha与300 mm）。在休耕季种植黑麦覆盖作物，可在所有处理的基础上进一步减少约50 kg N/ha/yr的淋失量。上述结果表明，推广养分与节水管理措施，可在不影响作物产量的前提下，实现硝酸盐氮负荷削减目标，满足环境保护与监管要求。 本研究成果发表于Rath S.、M. Zamora-Re、W. Graham、M. Dukes与D. Kaplan的论文《佛罗里达州苏旺尼河流域不同灌溉与养分管理措施下玉米-花生轮作系统地下水硝酸盐淋失量量化》，刊载于《Agricultural Water Management》（农业水管理），2021年，DOI: 10.1016/j.agwat.2020.106634。 用于模型率定与验证的试验数据存档于Zamora-Re, M.、J. Merrick、M. Dukes(2021)发布的数据集《佛罗里达含水层可持续合作参与项目（Floridan Aquifer Collaborative Engagement for Sustainability，FACETS）——佛罗里达州莱夫奥克田间试验数据》，存于农业数据共享平台（Ag Data Commons），DOI: 10.15482/USDA.ADC/1521079。