Integrated nutrient management: Integrated nutrient management (INM) aims at achieving a harmony in the judicious and efficient use of chemical fertilizers in conjunction with organic manures, crop residues, green manures, legumes in cropping systems, use of bio-fertilizers and other locally available nutrient sources for sustaining soil health and environment as well as crop productivity on long term basis.

Components of INM: Components of INM include judicious use of chemical fertilizers, organic manures, crop residues, green manures, legumes and biofertilizers.

1. Chemical Fertilizers: Use of chemical fertilizers in balanced proportions and recommended amounts is the quickest way of boosting crop production. Further, chemical fertilizers alone are unable to maintain and sustain the long term soil health and crop productivity because they are unable to supply organic matter and micro-nutrients like organic manures. Hence, the integrated use of inorganic fertilizers with organics increases the efficiency of applied nutrients and soil health.

2. Organic Manures: The organic manures which are mainly prepared from animal’s dung/urine and plant residues, are referred to as organic manures. FYM is the most important and commonly used organic manure in India. Common organic manures are FYM, compost from farm litter, night soil, sewage and sludge, green manure, poultry manure, vermicompost, biogas slurry, crop residues etc.

3. Legume Crops in Rotation: Legumes can form an important component of INM system when grown for grain or fodder in rice-wheat cropping system, intercropped with other non-legumes or when introduced as green manure crops. Legumes act as soil fertility restorers due to their ability to obtain N from the atmosphere in symbiosis with Rhizobium. It plays a vital role in N-fixation and economizing the N use.

4. Bio-Fertilizers: Bio-fertilizers are microbial inoculants of bacteria, algae, fungi alone or in combination and they augment the availability of nutrients to the plants. These microorganisms are used for the treatment of seeds, seedlings and application to soil or in composting to increase soil fertility and help in crop growth and high yield. Rhizobium, Azotobacter and Phospho-bacteria, BGA and Azolla are the major bio-fertilizers.