In environments where water is the limiting crop production factor, precision agriculture efforts must focus on tailoring site-specific management in relation to yield potential as governed by growing season water supply. The purpose of this research was to determine optimum plant populations for varying levels of growing season water supply. These data would then be used in the implementation of economically viable seeding rate prescriptions. Three locations in Northeast Kansas and three locations in the western Kansas High Plains were involved in the study. Varying levels of information were available for each field; at most including 15 and 1/3 bar water capacities, shallow electrical conductivity, DGPS elevation data, soil sample information, and yield history. In the fields with the most comprehensive datasets, attempts were made to generate seeding rate prescriptions based upon physical soil properties affecting growing season water supply.  In fields with less complete datasets, sites were selected for their inherent spatial variability, and then seeded with strips of varying populations and hybrid maturities. These sites were selected with the assumption that spatial yield variability results from spatial variability of growing season water supply. Additional data will be collected from the sites and post-harvest data analysis will attempt to determine optimal plant population based on measured or sensed physical soil properties. Improvements in understanding optimal plant populations and maturity based on measured or sensed physical soil properties will aid in creating economically viable site-specific seeding decisions.