Application and Management of Nitrogenous Fertilizer in Rice Field: A Review

Rice (Oryza sativa L.) is one of the most significant cereal in the world. Globally, the top rice producing country is China, while India is the world’s second largest producer and the largest exporter of rice in the world. It covers one-third of the total cultivated area in India as it is one of the major staple food crops. The application of nitrogenous fertilizer in crop production system is an important aspect of modern crop management practices and one of the determining factors to increase crop yield and thereby keeping pace with the expanding human population. Rice production can be increased by the application of nitrogenous fertilizer whether organic or inorganic at an appropriate time and place. The fertilizer should be applied in multiple split doses depending on the soil’s nutritional status, crop demand and the sources of nutrients. However, most of the nitrogenous fertilizer applied to rice fields is not taken up by rice plants but instead lost to the environment as ammonia, nitrate and nitrous oxide. The ‘reactive N’ also known as fixed N has a negative impact on human health as well as causes serious environmental problems. Surface runoff, denitrification, ammonium volatilization and leaching should all be managed in order to reduce the nitrogen loss from rice fields. Sustainable and environmentally friendly fertilizer management techniques raise the crop yields and enhance the sustainable soil fertility status. So it is necessary to implement management practices in order to reduce nitrogen losses and increase the nitrogen use efficiency (NUE) in rice production.