RESPONSE OF WHEAT TO IRRIGATION UNDER SHALLOW AND DEEP GROUND-WATER TABLE SITUATIONS

Field experiments were conducted on wheat during winter seasons of 1983-84 to 1985-86 on Typic Ustochrept loam soil under shallow and sandy loam under deep ground water situations, at the Indian Agricultural Research Institute, New Delhi with, (i) no post-sowing irrigation, (ii) irrigation at CRI, (iii) irrigations at CRI and flowering, (iv) irrigation at CRI, boot and milk stages and (v) irrigations at CRI, jointing, ear emergence and milk stages of the crop. Depth to water table during crop growth varied from 125 to 165 cm under shallow and 255-335 cm under deep water table situations. Rainfall received during first, second and third seasons was 14.9 mm, 10.4 mm and 111.0 mm, respectively. Grain yield under shallow water table conditions increased progressively with irrigations during low rainfall seasons and only up to one irrigation when good rainfall was received but in all the seasons under deep one. Saving of one to two irrigation was possible to act practically similar yield when wheat was grown under shallow water table (125-165 cm) compared to deep one. The mean seasonal consumptive use of water varied from 210 to 380 mm under shallow and from 200 to 374 mm under deep water table situations.