Adapting Nitrogen Management to Climate Change: Evidence from On-farm Field Experiments in Iowa
Eseul Choi, Guilherme DePaula, Peter Kyveryga, Suzanne Fey
May 2023 [23-WP 649]
Choi, E., G. DePaula, P. Kyveryga, and S. Fey. 2023. "Adapting Nitrogen Management to Climate Change: Evidence from On-farm Field Experiments in Iowa." Working paper 23-WP 649. Center for Agricultural and Rural Development, Iowa State University.
Climate change will likely increase the intensity of rainfall and therefore the probability of nitrogen leaching in agriculture. The more nitrogen leached through soils, the less nitrogen available for plant growth and the higher the likelihood of polluted water streams. We combine the effect of excessive rainfall on crop productivity and on water pollution in a simple economic model for nitrogen management and then estimate the model using experimental data from the Iowa Soybean Association. We find that the productivity effect is three times higher than the pollution effect. An increase in excessive rainfall induced by climate change would increase both water pollution and the cost of controlling nitrogen pollution because nitrogen becomes more productive. There is potential for adaptation as the probability of N leaching under excessive rainfall increases from 32% to 77% depending on the farmer's choice of crop rotation and the timing and form of N fertilization.