Department of Soil Science, CCS Haryana Agricultural University, Hisar, 125004.
An experiment was conducted in lysimeters during 1994 and 1995 to estimate contribution of groundwater to evapotranspiration (ET) needs of sunflower (Variety Morden) under three pre-fixed water table depths of 60, 90 and 120 cm with three irrigation levels of no post-sown irrigation, post-sown irrigation at IW/CPE ratios of 0.3 and 0.6. In both the years, significantly higher grain and straw yields were obtained when the water table depth was kept at 60 cm as compared to that at 90 and 120 cm. The grain yield was also found to be increased with increase in post-sowing irrigation frequency. Groundwater contribution to the ET was maximum when there was no post-sown irrigation and the water table was at a depth of 60 cm. A decrease in the groundwater contribution to crop ET was observed with increase in water table depth and number of irrigations.
Evapotranspiration, groundwater contribution, shallow water table depth, irrigation frequency
