Need for Integrated Nutrient Management
During the last decade of the 20th century, the long term effects of using chemical fertilizers were analysed and the nee of integrated nutrient management (INM) was felt all over the world, and particularly in India. Following were the results of the above analysis of long term effects of chemical fertilizers, which call for immediate implementation of INM : (i) Unbalanced use of N:P:K have caused deleterious long term effects on soil fertility; (ii) in areas subjected to intensive cultivation, application of mere chemical fertilizers (N:P:K) is not sufficient for sustaining the yields, and it also leads to deficiency in the soil for secondary nutrients and micro nutrients which limit crop productivity; (iii) use of organic manure, green manure, crop residue and biodegradable rural and urban waste not only supplement the chemical fertilizers, but also increase the efficiency in nutrient supply, leading to improvement in physical and biological properties of the soil. It has therefore been recognized that long term sustainable crop productivity that long term sustainable crop productivity can only be achieved if optimum doses of N:P:K are supplemented with the application of 10 to 15 tonnes of FYM per hectare annually (FYM = Farmyard manure).