Impact of alternate wetting and drying irrigation and brown manuring on water use, weed control and yield of drum seeded rice

Abstract

Direct-seeded rice (DSR) is a cost-effective and environmentally friendly method of crop establishment. Weed menaces in DSR considerably reduce the yield potential, which can be addressed by effective irrigation and weed management practices. Information on the impact of various water-saving irrigations and brown manure (BM) on water use, weed studies, and the yield of drum-sown rice is very limited. A field investigation was conducted to determine the effects of alternate wetting and drying irrigation (AWDI) methods (10 cm, 15 cm dropped from FWT and farmers practices) and BM (Sesbania at 15, 20 and 25 kg ha-1, Pretilachlor 0.45 kg ha-1 as PE fbBispyribac Na 25 g ha-1 as PoE + hand weeding (HW) on 45 DAS, HW at 20 and 45 DAS, and weedy check. The results revealed that AWDI at 15 cm depletion of FWT with HW on 20 and 45 DAS increased the water use efficiency (5.3 kg ha mm-1), water productivity (0.53 kg m-3), water saving percentage (35.83%), and reduced the water consumption (770 mm). Continuous submergence with HW at 20 and 45 DAS significantly increased grain (4.4 t ha-1) and straw yield (6.5 t ha-1). At the same time, it reduced the grasses (53.3 and 58.4%) and sedges (76 and 75%), density and dry weight, respectively, over AWDI at 10 cm dropped from FWT. Thus, irrigation at 10 cm below FWT with sesbania BM at 20 kg ha-1 could be recommended for higher productivity of drum-sown rice under sodic soil conditions.