ARS | Publication request: NUTRIENTS IN THE ENVIRONMENT: TARGETING SOURCES AND ABATEMENT

Submitted to: Proceedings of the Water and the Future of Kansas Conference
Publication Type: Abstract Only
Publication Acceptance Date: March 20, 2003
Publication Date: March 25, 2003
Citation: Meisinger, J.J., Sharpley, A.N., Schepers, J.S. 2003. Nutrients in the environment: targeting sources and abatement. Proceedings of the Water and the Future of Kansas Conference.

Technical Abstract: Watershed studies have shown that implementation of conservation or nutrient management strategies, to reduce non-point N and P losses, must be carefully selected and targeted to be effective. Generally, N losses are more management sensitive than P, with N loss management focusing on avoiding excess N in the soil profile to minimize nitrate leaching. However, avoiding excess N is dependent on temporally variable factors such as crop N uptake, excess precipitation, and denitrification. A N-indexing framework should thus include factors for N management (N source, rate, timing), soil physical properties (water holding capacity, drainage), site hydrology (precipitation regime, irrigation, drainage), cropping system (legumes, cover crops), and farming system (livestock stocking rate) to index a sites vulnerability to N loss. For P, an index has been adopted by most states by implementing a nutrient management planning strategy. Most P-indexes are based on identifying areas that have both a high P transport potential and a high P status, due to P soil test or P source management. Processes controlling N and P loss potential will be compared in terms of reliably identifying nutrient sources and targeting remedial efforts. The use of real-time imaging of N stress offers a valuable tool to improve real-time N management decisions, enhance N targeting, and increase N use efficiency with concomitant improvements in environmental quality.