INTEGRATED NUTRIENT MANAGEMENT IN SORGHUM (SORGHUM-BICOLOR) WHEAT (TRITICUM-AESTIVUM) CROPPING SYSTEM

An experiment was conducted during 1987-88 and 1988-89 to investigate the effect of organic and inorganic fertilizers, alone and in combination, on nutrient uptake, yield and the extent to which farmyard manure, crop residue and green organic matter could supplement nitrogen for sorghum [Sorghum bicolor (L.) Moench]-wheat (Triticum aestivum L. emend. Fiori and Paol.) crop sequence grown on a medium black soil. The results indicated the possibility to save N at least 25-50% by applying farmyard manure or green crop residue or green organic matter to sorghum For optimum economy, organic manure was applied to rainy-reason crop rather than to the winter crop, as their decomposition and assimilation were better during rainy season. Similarly, residual effect of organics was pronounced leading to increased average grain yield of wheat for 2 years (46.95 q/ha) in the treatments receiving 50% of recommended dose through farmyard manure + 50% through chemical fertilizer. Rainy-season treatment of 75% of recommended dose of NPK through fertilizer + 25% N through farmyard manure or through green organic matter gave grain yield of 45.44 or 48.08 q/ha of wheat as compared with 43.77 q/ha through chemical fertilizer applied in both rainy and winter seasons. Treatments where no fertilizer was applied in both seasons by any source of organic and inorganic gave only 14.81 q/ha of sorghum and 18.89 q/ha of wheat grain (average of 2 years) yields.