FERTILIZER MISAPPLICATION AND ECONOMIC ASSESSMENT OF SOIL FERTILITY DEGRADATION-A CASE STUDY IN NALATHWAD WATERSHED, KARNATAKA

Misapplication of fertilizer inputs has been found in practice both in general recommendations and farmers local practices. Fertilizer application as per general recommendations in general showed surplus addition of NPK nutrients than the required whereas nutrient misapplication on farmers fields varied with crop as well as category of farmers. In sorghum crop under farmer's level of management both N and P nutrients were used in excess, while in case of wheat and sunflower, the same nutrients (N and P) were applied in less than the required. With respect to K use, there was minimal or no use by farmers leading to large scale mining of soil K continuously in all the crops studied. The total misapplication (NPK) of nutrients in Nalathwad watershed (560 ha) as a whole was estimated to be 14.91 tons nitrogen, 2.68 tons phosphorus and 11.77 tons K, in terms of economic value it amounts to Rs. 292714.