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United States Department of Agriculture

Agricultural Research Service

Research Project: Spatial Modeling of Agricultural Watersheds: Water and Nutrient Management and Targeted Conservation Effects at Field to Watershed Scales

Location: Agricultural Systems Research Unit

Title: Modeling landscape-scale nitrogen management for conservation

Authors
item Ascough, James
item Delgado, Jorge

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: March 24, 2013
Publication Date: N/A

Interpretive Summary: NLEAP-GIS 4.2 is an advanced tool that can conduct a quick assessment of a large number of fields over a long-term scenario to identify hot spots across the landscape. One of the model’s capabilities is that it can connect to and use GIS soil databases from the USDA-NRCS which are readily available for download from the Internet. The model can also use NRCS weather databases which are also available for Internet download. Management scenarios to evaluate nitrogen (N) use efficiencies at a given field site are easy to develop and NLEAP-GIS 4.2 can be run to quickly assess crop-landscape combinations. These databases can be exported to the newer, more advanced NLEAP GIS 5.0 prototype which supports GIS-based simulations and displays N losses to the environment using GIS-integrated NASA WorldWindTM technology and tools for spatial statistical analysis. This publication provides instructions on how to conduct a hands-on exercise using a prototype of the NLEAP GIS 5.0 modeling tool. The user will be able to do quick evaluations across large areas and identify the effects of best nitrogen management practices. The user will also be able to perform a Nitrogen Trading Tool (NTT) analysis to determine the benefits of implementing best management practices across these landscapes. These tools are helping us to assess the benefits of using nitrogen management practices to increase nitrogen use efficiency which involves applying N at the right place and time using the right method and amount.

Technical Abstract: There are concerns about how agriculture will adapt to a changing climate and other environmental challenges during the twenty-first century to provide food security for the ever-increasing global population. Designing and implementing best nitrogen management practices will be key in global food security efforts because of the positive correlation between nitrogen inputs with crop yield and nitrogen losses to the environment. Computer models are important tools that can help nutrient managers implement conservation practices on the ground to improve nitrogen use efficiencies and reduce losses of nitrogen from agricultural systems. One such tool is the NLEAP-GIS 4.2 (as well as its newest version, the NLEAP GIS 5.0), which allows analysis of multiple fields simultaneously. To use the NLEAP-GIS 4.2 tool, users need to download GIS soil databases from the NRCS, download weather databases from the NRCS for the climate station nearest to where the analysis is going to be conducted, and develop the management scenario that they want to test. If desired, the more advanced NLEAP GIS 5.0 can be used to conduct GIS-based simulations and display N losses to the environment using the GIS-integrated NASA WorldWindTM technology and tools for spatial statistical analysis. This chapter includes a hands-on exercise that covers a prototype of the NLEAP GIS 5.0 model. The user will be able to do quick evaluations across large areas and identify the effects of best management practices. The user will also be able to perform a Nitrogen Trading Tool (NTT) analysis and determine the potential benefits of implementing management practices and the quantity of nitrogen savings that could potentially be traded in future air or water quality markets.

Last Modified: 7/24/2014
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