Field data were collected from experimental plots located near Grand Junction Colorado. Data collections were designed to provide a sufficiently broad range of conditions such that a simulation model could be verified. The experimental plots were planted to corn and were furrow irrigated. The basic management practices investigated were irrigation frequency, irrigation efficiency, and manure loading rate. Climatological conditions, soil moisture, potential evapotranspiration, and irrigation system performance were measured in the field. Soil samples and percolation water collected immediately beneath the crop root zone were analyzed for various nitrogen species, total organic carbon, and common salinity cations and anions. Model simulations were run for a wide range of typical Grand Junction conditions to evaluate the effect of irrigation and animal manure utilization practices on nitrate movement to groundwater.