The Spring Wheat Fertilizer Economics file has been updated to allow better analysis of protein premiums and discounts throughout the range of possible protein levels.

These programs allow the user to evaluate the optimal amount of nitrogen fertilizer to apply given the price of crop, spring wheat or winter wheat, the price of nitrogen per pound of active ingredient and protein discounts and premiums that may be available for either spring wheat or winter wheat. The yield response for S.W. and W.W. is estimated for soil N plus applied nitrogen and the yield response to total nitrogen is estimated using a model that allows the user to specific their estimated maximum yield given their historical experience.