Submitted to: Integrated Crop Management Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/18/1997
Publication Date: N/A
Technical Abstract: One of the most prevalent environmental issues throughout the Midwest is nitrate (NO3) contamination of surface waters. Non-point source pollution resulting from nitrogen (N) fertilizer use on artificially drained agricultural land has been identified as a major contributor to this problem. High levels of nitrate-nitrogen (NO3-N) in water supplies pose risks to humans and livestock, and have cost some communities millions of dollars for NO3 removal. Elevated N contents have altered natural aquatic floral and faunal population dynamics, exacerbated occurrences of eutrophication in lakes, reservoirs and hypoxia and anoxia of the Gulf of Mexico. Beginning in 1997, the USDA-ARS National Soil Tilth Laboratory (NSTL) initiated a watershed scale research project to evaluate the late-spring soil nitrate test (LSNT) program as a N management alternative for corn production and to determine its ability to reduce NO3 contamination of surface waters. This investigation, the Walnut Creek Nitrogen Initiative, evolved from an on-going water quality assessment study of an extensively tile-drained agricultural watershed that documented NO3-N concentrations at or above the maximum contamination level (MCL) of 10 ppm for extended periods of time. Our goal for the project is to determine the potential of a conservation-based N fertilizer program to serve as a management tool for corn production. Endpoints are reduced NO3 contamination in surface water and maintenance of economic viability when compared to conventional farming practices at the watershed scale.