MANAGING PLANT NUTRIENTS FOR OPTIMUM WATER-USE EFFICIENCY AND WATER CONSERVATION

This chapter focuses on macronutrient deficiencies and toxicities, although micronutrients occasionally enter the discussion. Sometimes it can be difficult to separate nutrient effects because of their interactions. For example, an excess of one nutrient can induce a deficiency of another nutrient. It is precisely these interactions—including nutrient, organic matter, and pesticide interactions with water and with each other, that are addressed in the chapter. Traditional agriculture has attempted to maintain soil fertility through use of mulches, crop residues, vegetative covers, and nutrient recycling. It is imperative that a balanced approach should be used in nutrient management so that neither food production nor water quality is sacrificed in exchange for the other. Nutrient management can be a tool for minimization of soil erosion. The utilization of legumes, cover crops, and crop residues as nutrient sources also results in reduced runoff and erosion. Fertilizers, organic or inorganic, can play an important role in improving yields on productive land and thus reducing the use of marginal, erodible land for crop production and can also be utilized for remediation of eroded land. The most obvious and direct impact of nutrient management is on nutrient contamination of surface and groundwater supplies. A balanced approach with long-term and worldwide vision is the key to sustainability. © 1994, Academic Press Inc.