Foltz, MaryLong, Elizabeth2024-05-152024-05-152023-12https://hdl.handle.net/20.500.14446/344278The use of nitrogen (N) fertilizers has allowed for increases in agricultural productivity. Excess N can be emitted to the atmosphere as nitrous oxide (N2O), which contributes to global climate change and stratospheric ozone depletion. Yield and N losses to the atmosphere can be modeled using the Denitrification-Decomposition (DNDC) model. The Testing Ag Performance Solutions (TAPS) program is a low-stakes competition in the U.S. Great Plains that encourages participants to be more efficient with their fertilizer and irrigation management. Previously efficiency efforts have been focused on yields and economics, but the program is interested in incorporating environmental impacts. The objectives of this study were (1) to evaluate and calibrate the DNDC model for corn yield predictions at the Oklahoma and Nebraska TAPS sites and (2) to estimate and compare yield weighted N₂O emissions from plots under different irrigation and fertilizer managements. Fields with differing amounts of fertilizer and irrigation were modeled for TAPS sites in Oklahoma and Nebraska using the DNDC model. Correlation analysis was done using Spearman’s rank correlation. The DNDC model mostly underpredicted the yield for both sites. Yield was more strongly correlated with irrigation than fertilizer application. Meanwhile, yield-scaled N₂O emissions were strongly correlated with fertilizer application, particularly in Oklahoma. Therefore, decreasing fertilizer application rates could decrease relative N₂O emissions without compromising corn yields as much as irrigation reductions would, particularly in Oklahoma. This work will help direct future fieldwork on the environmental impacts at the TAPS sites.application/pdfCopyright is held by the author who has granted the Oklahoma State University Library the non-exclusive right to share this material in its institutional repository. Contact Digital Library Services at lib-dls@okstate.edu or 405-744-9161 for the permission policy on the use, reproduction or distribution of this material.ThesiscornDNDCfertilizerirrigationnitrous oxide