Sunday, November 12, 2006
20-10

A New Tier One GIS-Nitrogen Index.

Jorge Delgado, USDA-ARS-Soil Plant Nutrient Res., 2150 Center Ave, Bldg D, Suite 100, Fort Collins, CO 80526 and Marvin Shaffer, Shaffer Consulting, 8225 Firethorn Dr, Loveland, CO 80538.

Nutrient managers and conservationists need tools to quickly assess effects of management practices on residual nitrate nitrogen (NO3-N) available to leach (NAL) across regions and the effects of high risk cropping systems/landscape combinations to reduce NO3-N leaching, atmospheric nitrogen (N) losses, and N losses due to surface runoff and erosion and potential off-site effects to aquifers and surface waters. The Delgado et al (2006 ) N-Index was tied up to a GIS system in order to quickly evaluate and conduct a Tier One analysis across a field with significant spatial variability and a region. The New GIS-N-Index version 1.0 (GIS_NI 1.0) was developed in an Excel format to facilitate the import and export of GIS database information into the N Index. We are going to present software that can be used to quickly use a new N-Index to quickly assess N management across high risk cropping systems/landscape combinations, and identify hot spots in the region. We are also going to present examples conducted across a field with different soil types and across a region and demonstrate how the new N Index GIS Tier One compare with Tier Two analysis conducted over the same area.