Economic feasibility of variable-rate technology for nitrogen on corn

The economic feasibility of three different fertilizer management strategie s (constant rate, three-rate and multiple-rate technology) in the applicati on of nitrogen fertilizer to corn are compared under different probability distributions for field fertility. A constant rate was more profitable than either variable-rate technology system for homogeneous fields with low fer tility. The application area at which the relative profitability between sy stems changed was largely determined by the characteristics of the fertilit y distribution rather than by assumptions regarding costs. Variable-rate te chnology improves groundwater quality in low-fertility fields by reducing t otal fertilizer applied and in high-fertility fields by increasing corn yie ld.