Effect of different sources of nitrogen on productivity, profitability and N useefficiency of fodder oat (Avena sativa)

A field experiment was conducted during the rabi season of 2020-21, to assess the effect of different source of nitrogen on fodder yield, economics and N use efficiency of oat (Avena sativa L.). The experiment consisted of seven treatments viz. control (no N); recommended dose of N (RDN); 50% N through fertilizer + 50% N through FYM; 50% N through fertilizer + 50% N through vermicompost; 50% N through fertilizer + two sprays of nano-urea; two spray of nano-urea and site-specific nitrogen management (SSNM). Results showed that application of 50% RDN through fertilizer + two sprays of nano-urea produced 58.3 t/ha green fodder which was at par with all other treatments except two sprays of nano urea and control. However, green fodder yield reduced under two foliar sprays of nano-urea by 20.7% as compared to 100% RDN (59.2 t/ha). The SSNM treatment recorded the highest net returns (` 49947/ha) and benefit to cost ratio (1.45) which were significantly higher than all other treatments except 100% RDN and 50% RDN through fertilizer + two sprays of nano-urea. The nano-urea treatments exhibited the highest nitrogen use efficiency. The study suggested that 50% recommended dose of nitrogen through con- ventional fertilizer along with two sprays of nano-urea could be applied in oat to get higher nitrogen use efficiency without any yield reduction.