EFFECT OF CONTINUOUS CULTIVATION OF FCV TOBACCO ON FERTILITY STATUS OF SOILS OF PERIYAPATNA IN MYSORE DISTRICT OF KARNATAKA

摘要

To monitor the changes in soil fertility status of Periyapatna taluk of Mysore district in Karnataka due to continuous cultivation of FCV tobacco for the last two decades, soil fertility survey was undertaken during April, 2004. Soil test summaries and nutrient index values revealed that the soil reaction, soluble salts and chloride content did not significantly vary in both surface and sub-soils due to continuous FCV tobacco cultivation. There was reduction in nutrient index values for soil organicmatter and available potassium, whereas nutrient index values for available phosphorus increased reflecting a buildup in available phosphorus and depletion in organic carbon and available potassium due to continuous FCV tobacco cultivation. Hence, optimum and balance dose of nitrogen and potassium fertilisers and a reduction in phosphate fertiliser dose (40 kg P_2O_5/ha) along with organic manures is suggested for sustaining the optimum NPK nutrition of the crop for higher tobacco leaf yields and for maintaining the major nutrient balance in these soils.