Managing Crop Nitrogen to Mitigate and Adapt to Climate Change.

Agriculture in the United States cycles large quantities of nitrogen (N) to produce food, fuel and fiber. Nitrogen lost from cropping systems can potentially move to waterways, groundwater, and the atmosphere. Changes in climate and climate variability may further affect the ability of agricultural systems to conserve N. There are many opportunities to mitigate the impact of agriculture on climate and the impact of climate agriculture through the management of the N cycle. Some are available today; many await further research and effective incentives to become adopted. The 4R Nutrient Stewardship framework embraced by the fertilizer industry is designed to engage stakeholders and provide voluntary incentives for agricultural retailers and service providers to engage in practical and structural changes, and is already beginning to do so. These changes are required to support better choices for source, rate, timing and placement of the N applied in field crop production.