Soil fertility is determined by three major elements namely Nitrogen, Phosphorus & Potassium (N, P, K) of which nitrogen plays a very important role. For this reason, Urea (Containing 46% of N) consumption is very high all over the world. Generally, the plants are able to recover a fraction of Nitrogen present in Urea and this fraction is known as Nitrogen Use Efficiency (NUE). This NUE stands anywhere between 30 to 50%. Thus, two third of Urea Nitrogen escapes from the soil in the form of nitrogen, ammonia and nitrates etc. and is not used by the plants. Engro Fertilizers, Pakistan, researched and experimented use of âAzadirachta indicaâ commonly known as neem oil as nitrification inhibiting agent.Â Based upon the results of extensive laboratory trials, coating urea with neem helps in slow release of nitrogen, nourishing the crops for a longer period. The process reduces pollution of groundwater. There is an increase in crop yield and also serves as an efficient natural insecticide. It also serves as an anti-caking agent and will reduce the amount of urea required by a plant by ~10-20%.
This paper explicates Engroâs experience and research on neem coated urea, methods of preparing an effective neem oil emulsion, quantities of raw materials to be used per unit of urea, its uses and results obtained after extensive laboratory and commercial trials.