Soil-Water balance components and water use efficiency of different crop sequences grown on a vertisol

A field experiment was conducted during 1988–89 to 1992–93 to study the effect of moisture regimes in soil-water balance components, economic returns, water use efficiency and soil health under six crop sequences, viz. cotton-summer groundnut, sorghum-wheat, sorghum-safflower, sorghum-gram, soybean-sorghum and pre-monsoon groundnut-sorghum grown in Vertisols. The average run off and deep percolation losses were 14 to 20 and 22 to 25 per cent, respectively of the rainfall received during the rainy season. Irrigation schedule at 0.75 IW/CPE value for crops having high water requirement was found to be economically optimum. Cropping sequences having high water use efficiency were found to be remunerative in the order: sorghum-safflower > soybean-sorghum > sorghum-wheat> sorghum-gram > pre-monsoon groundnut - sorghum > cotton-summer groundnut. Five cycles of high water requirement crops particularly with high irrigation schedules adversely affected the soil characteristics as indicated by increase in EC, exchangeable sodium percentage, bulk density and decreased infiltration rate.