Environmental considerations for cotton fertilization

Cotton (Gossypium spp.) fertilization is conducted primarily with agronomic objectives. These objectives are commonly oriented toward optimizing lint yield and quality by maintaining good plant nutrition and health. Economic objectives are also often considered in terms of optimizing the return on the investment (lint production in relation to dollars expended on crop fertilization). Another set of considerations that are important in the fertilization of a cotton crop is that of environmental impacts. Cotton is a dynamic crop with respect to growth and yield, and therefore, the management of the vegetative/reproductive balance is very important. Accordingly, crop fertilization is important in relation to managing crop vigor and yield potential. The nutrients that are most susceptible to having a negative impact on the environment are those that are mobile in the soil system such as nitrogen (N) and sulfur (S). There is experimental evidence that crop fertilization can be managed so that agronomic, economic, and environmental efficiencies can be optimized simultaneously. Efficient crop fertilization needs to take into account the soil fertility levels for a given field, in-season crop conditions (e.g. fruit retention, vigor, and fertility status), stage of growth, and crop-specific nutrient demand characteristics. Providing applications of appropriate nutrients in-season can provide a good means of maintaining plant nutrition and fertilizer efficiencies.