Volatilization and leaching losses of nitrogen from different coated urea fertilizers

Fertilizers arc one of the costly inputs in agriculture and development of nutrient efficient fertilizers is need of the hour. Keeping in view of the above, slow release coated urea fertilizers are developed and the N loss from different coated urea fertilizers in a Vertisol was studied in comparison with normal urea. The coated fertilizers used were neem, 4% pine oleoresin (POR), 35% nano-rock phosphate and 2% nano-ZnO coated urea. In later two cases nanoparticles were loaded over 4% POR coated urea during preparation. Application of coated urea fertilizers such as neem coated urea and pine oleoresin coated urea in a Vertisol reduced the ammonia volatilization by 27.5% and 41.1%, respectively. Similarly, reduction of NO3-N leaching due to application of neem, resin, nano-rock phosphate and nano-ZnO coated urea were 18.3%, 28.0%, 25.7% and 35.1%, respectively. The reduction of N volatilization and leaching losses imparted by coated urea fertilizers could be a viable N source for crops. However field level validation experiments have to be carried out to assess the efficacy of these coated fertilizers in enhancing crop yield and nutrient use efficiency.