ON-FARM EXPERIMENTS ON NUTRIENT MANAGEMENT FOR MAXIMUM ECONOMIC YIELD OF SUGARCANE

摘要

Two on-farm experiments were conducted on farmers fields in Coimbatore district (Tamil Nadu) during 2004-06 to compare sugarcane yields and net returns from four nutrient management practices: (ⅰ) farmer's practice; (ⅱ) soil test based inorganic fertilizer; (ⅲ) integrated plant nutrient supply, and (ⅳ) new intervention (soil test based approach involved balanced application of organic manures, chemical fertilizers and biofertilizers). Productivity of the sugarcane plant-ratoon systems, in terms of cane yield/ha, was greater in integrated nutrient supply and new intervention plots than in soil test based inorganic fertilizer and farmer's practice plots. Juice quality parameters viz., sucrose per cent, purity per cent and CCS per cent progressively increased in ratoon crop as compared to corresponding plant cane. All nutrient management practices improved the net returns from sugarcane over the farmer's practice. The net returns advantage due to IPNS, new intervention and soil test based inorganic fertilizer over farmer's practice was to the tune of 31.25%, 26.41% and 27.53% respectively, in sugarcane plant-ratoon system. At both locations, B:C was greater with the soil test based inorganic fertilizer. Cost of production was reduced in ratoon cane by Rs. 26120/ ha (37.4%) from plant cane. The IPNS and new intervention treated plots resulted in significantly greater available Fe and Zn, and soil microbial biomass carbon and dehydrogenase activity over farmer's practice.