Cropping Systems Effects on Soil Quality in Semi-Arid Tropics

The rapid growth of human population in the developing countries necessitates developing strategies for sustainable food production through efficient use of natural resources. Use of subsistence agricultural practices has resulted in excessive removal of nutrients from the ecosystem, causing a negative balance of plant nutrients in soil. Chemical fertilizers used in combination with organic manures can effectively meet the nutrient needs of crops. Efficient use of chemical fertilizers requires an optimum level of organic matter in the soil, achievable by integrated use of nutrients through chemical fertilizers, organic materials or biosolids including composts and crop residues, inclusion of legumes in crop rotations, green manuring and use of bionutrients. Maintenance and improvement of soil quality through cropping systems is important to sustaining agricultural productivity. Soil quality enhancement requires improvement of soil physical, chemical and biological properties through improvement of soil structure, macro- and micronutrient status, soil organic matter content, and soil biodiversity. Several studies have documented the benefits of judicious use of chemical fertilizers and organic manures in maintaining soil quality and enhancing crop productivity. In addition, the importance of improved cropping systems, crop rotations and tillage practices in maintaining soil quality cannot be over-emphasized.