Cropping systems effects on soil quality in semi-arid tropics

The rapid growth of human population in the developing countries necessitat es developing strategies for sustainable food production through efficient use of natural resources. Use of subsistence agricultural practices has res ulted in excessive removal of nutrients from the ecosystem, causing a negat ive balance of plant nutrients in soil. Chemical Fertilizers used in combin ation with organic manures can effectively meet the nutrient needs of crops . Efficient use of chemical fertilizers requires an optimum level of organi c matter in the soil, achievable by integrated use of nutrients through che mical fertilizers, organic materials or biosolids including composts and cr op residues, inclusion of legumes in crop rotations, green manuring and use of bionutrients. Maintenance and improvement of soil quality through cropp ing systems is important to sustaining agricultural productivity. Soil qual ity enhancement requires improvement of soil physical, chemical and biologi cal properties through improvement of soil structure, macro- and micronutri ent status, soil organic matter content, and soil biodiversity. Several stu dies have documented the benefits of judicious use of chemical fertilizers and organic manures in maintaining soil quality and enhancing crop producti vity. In addition, the importance of improved cropping systems, crop rotati ons and tillage practices in maintaining soil quality cannot be over-emphas ized.