Monitoring soil quality changes in relation to land use and management in a watershed, Karnataka

Abstract

The study carried out in Rajankunte watershed between 1980 and 2002 indicated that the total cultivable land area reduced at the rate of 4, I ha annually, The reduction in area under food crops, agro-forestry and grazing lands has been diverted to horticulture, Nitrogen and phosphorus application in the watershed increased by 67 and 32 per cent over 22 years and, in general, nutrient application increased by 35 per cent The change in land use and nutrient use pattern resulted in increase in area under acid soils, decline in base saturation and soil organic carbon (SOC) in 0-30 cm layer at a faster rate, The change in land use and management greatly affects the soil quality and require immediate correction measures like lime application and soil and water conservation measures including proper crop rotations to arrest the further degradation, The total cost of correcting soil acidity using lime worked out to be ofRs 218802/- for the entire watershed and an average cost ofRs 7611- ha for improving soil quality in Rajanukunte Watershed,