Date of this Version
Roy Spalding and Martin Toavs (2012). REVISED 2011 Vadose Zone Nitrate Study at Hastings, NE.
In an effort to assist Hastings Utilities in the management of their well-head protection area (WHP A) and to protect the groundwater from the impact of nitrate loading from potential nonpoint and point sources, Hastings Utilities subcontracted with the Department of Agronomy and Horticulture at the University of Nebraska for deep vadose zone coring. Continuous 60-ft soil cores were obtained at 36 sites within the apparent WHP A (Figure 1). The sites were selected by Marty Stange on the basis of availability for sampling, management, landuse , cropping history, and location within the WHPA. Nitrogen analyses of these deep soil samples provide a baseline of vadose zone nitrate and ammonium concentrations. The results are used in this report to evaluate which agricultural practices within or near the WHP A significantly impact leaching of nitrate in the uppermost 60-ft of the unsaturated zone. The investigation is used to estimate whether improved water and nutrient management practices have a measureable effect on decreasing future nitrate loading to the groundwater beneath the WHP A. Such evaluations are useful in supporting improved practices that can lower nitrate loading in the capture zones of municipal wells.