RESPONSE TO CONSERVATION MEASURES IN A RED SOIL WATERSHED IN A SEMI- ARID REGION OF SOUTH INDIA.

Abstract

ACHIEVEMENTS OF WATERSHED MANAGEMENT PROJECT INITIATED IN 1976 AND MONITORED IN 1979 FOR ITS IMPACT ON RESOURCE CONSERVATION AND PRODUCTIVITY INCREASE IN AN ALFISOL SEMI- ARID REGION OF SOUTH- INDIA HAVE BEEN HIGHLIGHTED . CONSERVATION MEASURES VIZ GRADED BUNDS IN ARABLE LANDS , CONTOUR TRENCHES IN NON- ARABLE LANDS COMBINED WITH GULLY TREATMENT , REDUCED ANNUAL RUNOFF FROM 17 TO 2.3 % , PEAK RATE OF RUNOFF FROM 15 TO 4.4 M3/SEC AND SOIL LOSS TO 1.1 T/HA/YEAR. CONSERVATION OF RAIN WATER , COUPLED WITH IMPROVED PRACTICES , INCREASED FOOD PRODUCTION FROM 42 TO 78 T/YEAR OVER 103 HA UNDER DRYLAND CONDITIONS. AS A RESULT OF CONSERVATION AND GULLY CONTROL MEASURES , A SURFACE WATER STORAGE OF 6110 M3 WAS CREATED ACROSS THE WATERSHED WHICH RESULTED IN 14% OF THE ANNUAL RAINFALL BECOMING GROUND WATER RECHARGE. THIS IS REFLECTED IN THE INCREASE IN IRRIGATED AREA UNDER THE WELLS LOCATED IN THE WATERSHED FROM 19 HA IN 1985 TO 1986 TI 56 HA IN 1993 TO 1994. THE AVERAGE COST OF SUCH DEVELOPMENT WORKED OUT TO RS 752 PER HA AT THE 1979 PRICE LEVEL. THE OVERALL PROJECT GAVE A COST- BENEFIT RATIO OF 1.53.