Estimating Fertilizer Requirement

Farmers apply fertilizers to crops in order to produce maximum economic return. To attain this, it is important that fertilizer requirements can be estimated accurately. The prevention of excessive use of fertilizers on economic grounds also has the beneficial consequence of minimizing environmental pollution of groundwaters through the leaching of unused fertilizers. This work is intended for both the agricultural scientist who is engaged in research on the use of fertilizers in crop production and consultants who might assist with the interpretation of statistical data. Relevant mathematical and statistical procedures are described critically, indicating their bases and limitations, and how they may be used or misused. Some basic knowledge of statistics is assumed on the part of the reader. Many of the procedures have been developed by the author from experience in soil fertility projects in a number of less-developed countries.