ABSTRACT
Nutrient mining in many developing countries and excessive fertilization in developed countries have led to soil fertility decline and environmental degradation, respectively. Therefore, the need of integrated nutrient management (INM) through a judicious integration of mineral and synthetic fertilizers, crop residues, green manures, organic manures of plant or animal origin, recyclable organic wastes from industry and households, and microbial inoculants to maintain soil fertility for sustaining the desired level of crop productivity is widely felt. While maintaining soil productivity, the INM also ensures environmental quality and promotes changes in land use, crop rotations, and interactions between livestock and cropping systems. Such integrated applications are not only complementary but also synergistic as organic inputs have beneficial effects beyond their nutrient content. Many long-term experiments have shown that the integrated use of chemical fertilizers and organic manures has not only increased crop productivity but also resulted in increased nutrient use efficiency, buildup of soil organic carbon and other nutrients in soils, decreased nutrient losses, and consequently avoidance of environmental degradation. This entry provides a review of current information on INM and its components. It describes the role of chemical fertilizers and organic manures as well as the non-conventional mineral fertilizers such as phosphate rock and biofertilizers such as nitrogen-fixing biofertilizers (e.g., rhizobium, azetobactor, blue green algae), phosphate-solubilizing bacteria, and mycorrhizae in the INM system. It concludes that the improved understanding of nutrient availability from the above-mentioned resources and fate of nutrients in an integrated (soil-plant-water- air) system is required as they affect chemical, biological, and physical functions of soils for sustainable production and environmental protection.
