A Note on the Fertilizer Ratio Concept

The concept of plant nutrient ratios has long been utilized by agronomists and appears to be particularly prevalent in Pakistan. Production experts often express concern that the nutrient ratios utilized by the farmers are not optimum for a particular crop [4]. These concerns are reflected in the press and are considered by those charged with planning production and imports. Agronomists interested in plant nutrients may thus find themselves designing experiments to determine the optimum ratios of plant nutrients for different crops grown under different conditions. For the sake of simplicity we will limit this discussion to two nutrients, nitrogen and phosphorus and the resulting N/P ratios. This is appropriate because these fertilizer elements are the most widely used in Pakistan and crops often respond to their use. However, combinations involving other nutrients or crop inputs are subject to the same principles.