Division of Agronomy, ICAR-Indian Agricultural Research Institute, New Delhi 110 012, INDIA, Email: [email protected]
Nitrogen use efficiency (NUE), expressed as agronomic efficiency, of prilled urea is quite low under lowland rice in India. Among the different strategies used for enhancing agronomic efficiency of fertilizer N, use of enhanced efficiency fertilizers holds a great promise. Therefore a field experiment was conducted at the Research Farm of ICAR-Indian Agricultural Research Institute, New Delhi for two consecutive years. Main objective of the study was to find out the effect of essential and vegetable oils coated prilled urea on grain yield and agronomic efficiency of rice. The treatments (22) comprised of combinations of 3 N rates (50, 100 and 150 kg N/ha) and 7 N sources (citronella oil, meliacins, karanj oil, lemongrass oil, cottonseed oil, palmarosa oil and no oil coated prilled urea) at a thickness of 1000 mg oil/kg urea, and an absolute control. The experiment was laid out in a Randomized Block Design with three replications. Rice grain yield increased significantly up to highest N rate (150 kg/ha). All the oil coated ureas, except palmarosa oil, produced significantly higher rice grain yield over uncoated urea. Citronella oil coated urea produced highest grain yield of rice, being at par to karanj oil and cottonseed oil coated urea, but significantly higher than other coated ureas. The highest agronomic efficiency of nitrogen was recorded with citronella oil coated prilled urea.