Journal of the Indian Society of Soil Science

The long-term effects of fertilizers and manures on the yield of sorghum-cumbu rotation and soil fertility build up are being studied under dry farming in a Vertisol since 1982. The data on yield show that the application of Zn₅O₄ at 25 kg ha⁻¹ is highly essential over the recommended dose of Nand P for sustaining the yield of sorghum and cumbu over years. The inclusion of organics in the treatment schedule maintained higher organic carbon status and highest available N, P and K, thereby sustaining the soil health. Significant positive correlation coefficients were obtained with available N, available K and DTPA-Zn wiht sorghum and organic C, available N, available P and DTPA-Zn with cumbu yield. The omission of K in the fertilizer schedule has caused a continuous depletion in the NH₄OAc-K status over years.