Simulating the effect of perennialized cropping systems on nitrate-N losses using the SWAT model

Several newly released crop varieties, including the perennial intermediate wheatgrass (grain marketed as Kernza®), and winter hardy oilseed camelina, have been developed to provide both economic return for farmers reduced nutrient losses from agricultural fields. Though studies indicated that these crops could reduce nitrate-nitrogen (N) leaching, little research has done determine their effectiveness in reducing nitrate-N loading surface waters at a watershed scale, or comparing performance more traditional crops, such alfalfa. In this study, were predicted using Soil Water Assessment Tool (SWAT) model Rogers Creek located south-central Minnesota, USA. Predicted looses of under three perennialized cropping systems compared given current practices corn ( Zea mays L.)-soybean Glycine max L. Merr.) rotation. The included separate rotations: (IWG) rotation with soybean, alfalfa corn, camelina soybean rye. Model simulation rotations required creation new files IWG within SWAT. These validated measured yield, biomass, data. results show particularly effective sediment areas watershed, but smaller reductions also achieved From predictions, achieving regional water-quality goals 30% reduction load fields converting approximately 25, 34, 57% corn-soybean area alfalfa, IWG, rotations, respectively. Results study indicate adoption achieve water quality goals.