Chemical fertilizers

A simple way to correct some soil nutrient deficiencies is through the application of chemical fertilizers. Their expense may discourage or limit their use in many areas, but applications in small experimental plots are useful in demonstrating their potential and evaluating their feasibility in a specific area.

The meet commonly encountered fertilizer are in granular form and contain compounds of nitrogen, phosphorous, potassium, or a mixture of the above. The type of fertilizer and the amount to be used generally are given as recommendations accompanying soil analysis results. In applying such fertilizers, it is important to calculate from the given recommendation the quantity that must be applied in each furrow or at each plant to avoid under- or overapplications.

The timing of fertilizers applications is also important. For example in corn, a formula containing both phosphorous and nitrogen is usually recommended at planting time, while nitrogen only, in the form of urea, is usually recommended about one month after planting. Since fertilizer recommendations vary widely based on the soils and the crop to be planted, specifics concerning their use are not discussed here. A mare thorough discussion of fertilizer use is given in "Soils, Crops, and Fertilizer Use: A Guide for Peace Corps Volunteers".

Extensionists should familiarize themselves with the fertilization practices in use throughout their zone in order to determine if changes in the types, amounts, and/or timing of fertilizer applications would be beneficial.