Determining Profitable Use of Fertilizer

Excerpts from the report Introduction: The chief aim of this report is to illustrate procedures for developing yield response curves and related steps involved in determining profitable use of fertilizers. However, considerable interpretive discussion is included. This report is technical and is designed for use of production economists and agronomists. Emphasis is placed on methods and procedures, including preparation of materials, that could be used by extension workers and other agricultural leaders in discussing economic aspects of use of fertilizer with farmers. In addition, suggestions are made as to experimental designs for development of response data that would be particularly useful for purposes of economic interpretation. Profitable use of fertilizers depends on the physical response obtained and on prices of crops and costs of fertilizer. Crop response to all yield-influencing factors and returns per dollar cost from each would need to be taken into account in deciding upon the most profitable combination of all factors. Results from such a field of study would be particularly important to farmers who lack funds to carry each input to the point of its most profitable return. But such a study requires a knowledge of costs and returns from all factors used in producing the crop. Or, looking at the farm as a whole, it involves knowledge of comparative returns from all factors of production when they are devoted to different crop and livestock enterprises. Fertilizer response curves are only one of the keys to such information. Therefore, this report is limited to the problem of the rates and combinations of applied plant nutrients that will give the highest returns with respect to fertilizer.