Impact of nitrogen levels on crop productivity, farm profitability and nitrogen remobilization of Shahsarang and Mendri varieties of rice

A field study was conducted for rice crops on a lowland rice field of the Indian Council of Agricultural Research (ICAR) Research Complex for the Northeastern Hill Region (NEH), Umiam, Meghalaya, India, during kharif 2023. In the present study, five different nitrogen treatments were imposed separately on two varieties - Shahsarang and Mendri, including control, 40 kg N/ha (50 % RDN), 60 kg N/ha (75 % RDN), 80 kg N/ha (100 % RDN) and 100 kg N/ha (125 % RDN). The findings revealed that Shahsarang outperformed Mendri variety in terms of yield attributing characters and biological yield. Nitrogen treatments resulted in 1.1-1.3 times more grains per panicle compared to the control treatments for both varieties. The 100 kg N/ha resulted in the highest biological yield, which was statistically at par with 80 kg N/ha. Conversely, 80 kg N/ha led to the highest vegetative nitrogen remobilization. For both Shahsarang and Mendri, the 80 kg N/ha treatment showed the highest marginal return, approximately 1.3-4 times greater than other treatments. For Shahsarang and Mendri, the net returns were highest under 100 kg N/ha and were at par with 80 kg N/ha. Optimal growth, efficient nitrogen remobilization, the highest marginal return and improved grain yields can be achieved with the appropriate dose of nitrogen, particularly at 80 kg N/ha. These results emphasize the importance of site-specific nitrogen management to enhance both productivity and profitability in rice farming.