|RIBAUDO, MARC - Economic Research Serivce (ERS, USDA)|
|HANSEN, LEROY - Economic Research Serivce (ERS, USDA)|
|LIVINGSTON, MICHAEL - Economic Research Serivce (ERS, USDA)|
|MOSHEIM, ROBERTO - Economic Research Serivce (ERS, USDA)|
|WILLIAMSON, JAMES - Economic Research Serivce (ERS, USDA)|
Submitted to: United States Department of Agriculture Economic Research Service Proceedings
Publication Type: Research Technical Update
Publication Acceptance Date: 12/10/2010
Publication Date: 9/22/2011
Citation: Ribaudo, M., Delgado, J.A., Hansen, L., Livingston, M., Mosheim, R., Williamson, J. 2011. Nitrogen in agricultural systems: Implications for conservation policy. United States Department of Agriculture Economic Research Service Proceedings. 1.
Interpretive Summary: For all U.S. field crops planted in 2006 that received nitrogen fertilizers, 39 percent met all three of the nutrient management criteria. For the remaining 61 percent of cropland, improvements in method or timing of applications are required to improve Nitrogen Use Efficiency (NUE). Of all crops, corn is the most intensive user of nitrogen fertilizer, on a per-acre basis and in total use. Corn is also responsible for most of the nitrogen fertilizer that is not applied in accordance with the three management criteria. Incentives for improving NUE can come from increases in nitrogen prices, financial assistance, extending compliance to nitrogen management, and emissions markets. Improving on-field NUE can be supplemented with off-field filtering practices. Restored wetlands can be more cost-effective than vegetative filters where soil and hydrologic conditions allow. Policies for improving NUE must be cognizant of the potential environmental tradeoffs when particular issues related to reactive nitrogen are addressed. Reactive nitrogen is easily converted to forms that are readily transported by hydrologic and atmospheric processes. Focusing strictly on one issue, such as nitrate leaching, could lead to increase emissions of other nitrogen compounds, such as nitrous oxide, even when total reactive nitrogen emissions are reduced.
Technical Abstract: Nitrogen is an important agricultural input that is critical for providing food to feed a growing world population. However, the introduction of large amount of reactive nitrogen into the environment has a number of undesirable impacts on water, terrestrial, and atmospheric resources. Careful management could better balance nitrogen inputs with the need of crops, reducing losses to the environment. A variety of policy instruments exist for improving nutrient management in agriculture so that environmental externalities are reduced. Designing an efficient policy requires that factors influencing fertilizer use be fully understood. Also, an understanding of how farmers are likely to respond to different incentives would enable resource managers to assess potential environmental tradeoffs, driven by nitrogen’s ability to change forms and cycle through different environmental media. This report explores the use of nitrogen in U.S. agriculture, and assesses the improvements most needed to improve nitrogen use efficiency. It reviews a number of policy approaches for improving nitrogen management, and identifies important issues affecting the policies potential performance.