NLEAP Simulation of Soil Type Effects on Residual Nitrate-Nitrogen and Potential Use for Precision Agriculture

Well water N03 --N concentrations in the central part of the San Luis Valley had been found as high as 72 mg N03 --N L-1. Precision management practices according to differences in soil type found under a center pivot irrigation sprinkler may have the potential to improve N-use efficiency. No Nitrogen Leaching Economic Analysis Package (NLEAP) model simulation of effects of different soil types and crops on residual soil N03 --N (RSN) has been conducted under a similar irrigation system. Lettuce (Lactuca sativa L. ), potato (Solanum tuberosum L ), winter cover rye (Seca/e cereale L.), and winter wheat (Triticum aestivum L.) were grown on sandy loam and loamy sand areas of a center-pivot. A new NLEAP 1.2 version simulated soil type and crop effects on RSN (P < 0.001). NLEAP is a potential technology transfer tool that can be used to protect water quality by evaluating the effects of crops and soil types on RSN and can potentially be used with precision agriculture management practices.