|Shaffer, Marvin - USDA-ARS RETIRED|
|Lal, Harbans - USDA-NRCS, PORTLAND, OR|
|Mckinney, Shaun - USDA-NRCS, PORTLAND, OR|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 19, 2007
Publication Date: November 4, 2007
Citation: Delgado, J.A., Shaffer, M.J., Lal, H., Mckinney, S. 2007. Assessment of Delta Nitrogen Losses (Delta NL) at the Field Level. ASA, CSSA, SSSA Annual Meeting, New Orleans, LA Nov. 4-8-20076. CD-ROM. . ASA-CSSA-SSSA Annual Meeting Abstracts. Technical Abstract: We defined a new concept of field-level delta nitrogen (N) losses (Delta NL) as a comparison between management scenarios. We defined delta nitrogen losses (Delta NL) as a function of improved N use efficiencies of field management scenarios that reduce the average N inputs and/or modify other management practices thus lowering N losses from a farm field. The 'elta NL refer to potential downstream reductions in nonpoint source nitrogen loading of streams or other water bodies and/or in reduced loading of the atmosphere with N-associated greenhouse gases from agriculture. Nitrogen credits as traded on the Communities Market commonly refer to discounted reductions in agricultural nitrogen losses that apply to a project downstream from an agricultural area. We used a newly released Windows XP version of the Nitrogen Losses and Environmental Assessment Package (NLEAP) with a Geographic Information System (GIS) capability (NLEAP-GIS) to assess no-till systems from a humid North Atlantic US site, manure management from a Midwestern US site, and irrigated cropland from an arid Western US site. The new NLEAP-GIS can be used to quickly identify the best scenario that shows the greatest potential to maximize field-level Delta' NL for environmental conservation.