Effect of deficit irrigation on raised bed wheat cultivation

The experiment was conducted during Rabi season of 2015-2016 and 2016-2017 at the Regional Agricultural Research station, BARI, Ishurdi, Pabna, Bangladesh, to determine the water requirements of wheat on raised bed and the effect of different deficit irrigation on yield, water use efficiency and applied water productivity under raised bed wheat. This study consisted of following irrigation treatments: T1 = Irrigations up to 100% field capacity (FC) at crown root initiation (CRI), botting and grain filling stages (flat bed), T2 = Irrigations up to 100% FC at CRI, botting and grain filling stages on raised bed, T3 = Irrigations up to 80% FC at CRI, botting and grain filling stages on raised bed and T4 = Irrigations up to 60% FC at CRI, botting and grain filling stages on raised bed and laid out in a randomize complete block design with three replications.The result showed that significant effect of irrigation treatments were observed on plant height, spike per m2 and grain yield. Highest grain yield (4.66 t/ha) was obtained from treatment, irrigations up to 100% FC at CRI, botting and grain filling stages on raised bed, followed by irrigation up to 100% FC at same stages on flat bed. At raised bed wheat cultivation saving 14.30% water with increasing 15.66% grain yield than flat bed. Besides, comparing deficit irrigation (20% and 40% of full irrigation) and full irrigation condition on raised bed seeding system water use could be reduced about 4.18% to 5.57%, while scarifying 18.20% to 32.33% grain yield, where reduced 14.17% to 27.54% water use efficiency. Maximum applied water productivity 1.81 kg m-3 was observed in raised bed full irrigation condition. The rate of daily evaporation started to increase as the temperature started to rise and humidity started to decrease during the crop growing period. The results will be helpful for taking policy decision regarding efficient irrigation and water management under prevailing water scarce situation