Effect of integrated use of organic manure, green manure and fertilizer nitrogen on sustaining productivity of Rabi sorghum-chickpea system and fertility of a vertisol

The effect of integrated use of organic manure, green manure and fertilizer N on nutrients status of soil and productivity of rabi sorghum-chickpea system was studied in a field experiment conducted during 1996–97 and 1997–98 with various treatment combinations including FYM, compost, vermi-compost, green manure and fertilizer N. The differences in organic carbon, available N, P and K were significantly influenced. The organic carbon and available N status declined with application of fertilizer N alone and increased with conjunctive use of fertilizer N and organic manure. The combined application of organic and inorganic N sustained the productivity. Soil available nutrients like N, P and K increased significantly with the application of various organic sources of nutrients in combination with fertilizers over the fertilizer alone. The highest grain yield of rabi sorghum and chickpea was obtained with 50 per cent N through green manure plus 50 per cent fertilizer N.