Long Term Effects of Integrated Nutrient Management on Crop Yields and Soil Fertility Status in Vertisols of Bellary

The long term field experiment conducted at Bellary from 1978 to 1993, indicated that significantly higher grain yield of maize over control was observed with application of FYM @ 5 t/ha and NPK on recommended basis (3916 kg/ha) followed by application of FYM @ 5 t/ha plus NPK on soil test basis (3752 kg/hal and both the combinations were at par. Application of NPK on soil test basis recorded significantly higher safflower yield of 796 kg/ha and was at par with all the treatments, except, control and nutrient supply through Organic source alone. Significantly higher yields of bengalgram (1375 kg/hal was observed with application of N, P and K fertilizers on recommended basis. Application of orgafllc manure alongwith Nand P resulted in considerable build up of organic carbon and total nitrogen which was 21 and 59 per cent higher over control. The available potassium build up was maximum only in organic manure treatment. It has been further observed that considerable build up of phosphorus from 4.8 to 33.5 kg/ha has been noticed under treatment involving application of organic manure and NPK.