Effect of irrigation scheduling and residue management tillage on soil water balance and growth of wheat

Abstract The present study was conducted in wheat at the Punjab Agricultural University Seed Farm, Ladhowal, Ludhiana, to study effect of three irrigation regimes ( based on IW/PAN-E ratio of 0.6 (I1), 0.8 (I2) and 1.0 (I3) in main plots and four tillage practices (mould board ploughing to a depth of 25 cm followed by rotavator (PT25 + R), mould board ploughing to a depth of 14 cm followed by rotavator (PT14 + R), zero tillage with happy seeder (ZT) and conventional tillage with 2 discing + 2 cultivator followed by planking (CT) in sub plots) on soil water balance and crop growth for two consecutive years (2016-17 and 2017-18). Irrigation scheduling and tillage practices has no significant effect on plant germination and thousand grain weight. However overall mean plant height, leaf area index, root length density and root mass density were significantly higher in I3 over I1 and I2 by 2.1 & 2.8%, 16.82 & 7.75%, 2.04 & 5.22% and 5.82 & 8.73% respectively. During both the years straw and grain yield were significantly higher in I3 over I1 and I2. Significantly higher water productivity was observed in I2 over I1 and I3 by 27.38 & 2.26% in 2016-17 and 27.70 & 1.91% in 2017-18. During 2016-17 maximum water depletion was in I1 over I2 and I3 by 2.15 &4.86% and 4.5 & 7.52 in 2017-18. Over PT14 + R, ZT and CT, the tillage practice of PT25 + R significantly increased number of tillers by 5.13,19.42 & 11.82%, plant height by 3.44, 8.38 & 10.37%, leaf area index by 13.45, 26.17 & 27.36%, root length density by 19.30, 61.81 & 46.17% and root mass density by 35.90, 317.67 & 48.16% respectively. During both years significantly higher straw and grain yield were observed in PT25 + R over PT14 + R, ZT and CT. During both years significantly higher soil moisture storage was observed in I3 and ZT compared to other irrigation and tillage practices. Water balance component E&T were higher in PT25 + R than ZT.