Balance sheet of soil available nitrogen and economics of rice fallow sorghum at different planting densities and nitrogen levels

A field experiment was conducted during 2014–2015 to study the effect of planting density and N levels in zero till sorghum in randomized block design with factorial concept and was replicated thrice. The treatments comprised three planting densities viz S₁ (3.33 lakh plants/ha), S₂ (2.22 lakh plants/ha) and S₃ (1.66 lakh plants/ha) allotted to factor-A and four nitrogen levels viz N₀ (0 kg/ha), N₁(50 kg/ha), N₂(100 kg/ha) and N₃(150 kg/ha) allotted to factor-B. Maximum grain yield of sorghum and the economic returns were obtained at a plant density of 2.22 lakh plants/ha with the application of 150 kg N/ha. Maximum net balance of nitrogen was recorded with increased nitrogen and spacing. The application of 150 kg N/ha with a plant density of 2.22 lakh plants/ha gave the highest net returns (Rs 64921) and B:C ratio (2.74).