Controlled Release of Nutrients for Soil Productivity- A Review

The nutrient release from conventional chemical fertilizers to the soil are lost continuously through leaching, runoff, volatilisation, denitrification etc and also most of the time they do not satisfy the plant requirements without the continuous application. These issues have caused economic loss as well as environmental pollution due to hazardous emissions and water eutrophication. Controlled release of nutrients through the application of slow/controlled release fertilizers and nanofertilizers are possible solutions, which provides their nutrients according to the requirement of crops. Release of nutrients from controlled release fertilizers are delayed by means of coating the soluble fertilizer core with porous semipermeable membrane. A variety of coating materials are developed for the preparation of controlled release fertilizers. The longevity of controlled release fertilizers (CRFs) depends upon the thickness of coating, temperature and moisture content. Nano technology is an emerging field, which also produce nanofertilizers based on CRFs are used for the increment of active fertilizer material in the field, as they present large surface area for the release of required nutrients to the plant in a controlled manner. Controlled release of nutrients has profound influence on soil properties and yield parameters of crops. The use of controlled release fertilizers (CRFs) starts to evolve as a promising direction offering an excellent means to improve management of nutrient application and by this reducing significantly environmental threats while maintaining high crop yields of good quality. Controlled release fertilizers allow the release of nutrients to be better matched with the life cycle of the plant.