Alternate wetting and drying irrigation technology for sustainable rice ( Oryza sativa ) production

The water saving technology for lowland rice cultivation was very crucial because of in the future irrigation water become scarce and competed with other sectors. The lowering of the availability of irrigation water had the impact for sustainability of rice production. The study revealed that treatment I 1 attributed by the highest total water use (1646 mm) and the lowest Water productivity (0.46 kg m −3 ) produced the highest grain yield (7.56 t/ha). Treatment I 5 and I 6 , on the contrary, gave the second highest yield (7.21 and 7.05 t/ha) and consequently the second highest water productivity (0.65 and 0.59 kgm −3 ) indicating quite a large water saving (26.6 and 35%) compared to treatment I 1 . The yields in treatments I 4 (6.0 t/ha) and I 8 (6.30 t/ha) were significantly lower at 5% level of significance compared to that of treatment I 1 . No significant effect was found for the AWD irrigation regimes on the post-harvest soil nutrient status. Reduced plant height, leaf area index, plant nutrient uptake, grain yield, straw yield and harvest index were found with the increasing water stress. The study emphasized that rice crop can be successfully grown by adopting an appropriate AWD irrigation regime without any significant yield decline under sandy clay soils.