Status of soil degradation in an irrigated command area in Chikkarasinakere Hobli, Mandya district, Karnataka

摘要

Of late, the crop productivity levels in many irrigated command areas have plateaued or started declining rapidly due to the deterioration of soil health. Unscientific and excessive irrigation, growing crops not compatible with the soils and unscientific management of soils are the main causes for the present situation. Waterlogging, increased salinity/sodicity, nutrient imbalance, shrinking diversity of micro-flora and fauna have become major constraints limiting the choice of crop and crop productivity. We present a study on this issue from the Cauvery command area. Detailed cadastral-level survey taken up to study the status of soil and other resources occurring in Chikkarasinakere block of Mandya district, Karnataka during 2010 has brought out the alarming state of land degradation observed in the area. Nearly 59% of the area is suffering from various degrees of chemical and physical degradation. The situation becomes alarming because the area had well-drained red soils highly suitable for irrigated agriculture when irrigation was introduced during 1930s. The process of degradation will accelerate if appropriate interventions/investments are not undertaken on priority. Continuation of present management practices can rapidly damage the soil health. As the command area is one of the important rice bowls of Karnataka, there is an urgent need to reverse the process of degradation by adopting site-specific interventions as indicated in the study. The present study reveals that the Cauvery command are in Karnataka is losing Rs 1000 crores every year due to this problem.