Vertical distribution of soil nutrients and its correlation with chemical properties in soils of Yavatmal district, Maharashtra

The application of fertilizers in site-specific crop production systems requires a detailed knowledge of the soil nutrient status. A detailed soil survey at 1:10000 scale in a Kupti micro-watershed (District Yavatmal, Maharashtra) revealed a considerable spatial variation of the nutrient levels. Ten soil series were tentatively identified after the survey and analysis. A representative pedon in soil series was analyzed for pH, electrical conductivity, organic carbon, calcium carbonate, cation exchange capacity, available nitrogen, available phosphorus, available potassium, available sulphur and DTPA-extractable micronutrients (Fe, Mn, Zn & Cu) using standard analytical methods. Based of fertility ratings, pH of soils was slightly acidic to strongly alkaline. Electrical conductivity was normal (<1.0 dS/m). Soil organic carbon was low to high and showed decreasing trend with depth. All soils are calcareous. Zinc was found below critical level whereas; iron, manganese and copper were estimated to occur above critical level. The pH of soil showed non-significant and negative correlation with nitrogen (r = -0.36), non-significant and positive correlation with phosphorus (r = 0.06), potassium (r = 0.11), sulphur (r = 0.25) and significant and negative correlation with iron (r = -0.96), manganese (r = -0.97), zinc (r = -0.71) and copper (r = -0.89). Soil organic carbon shows significant and positive correlation with nitrogen (r = 0.63), zinc (r = 0.61) and copper (r = 0.51) whereas it was non-significant and positive with all other nutrients. Calcium carbonate content of soil showed significant and negative correlation with nitrogen (r = -0.65), iron (r = -0.61), manganese (r = -0.61), zinc (r = -0.60) and copper (r = -0.63).