Boro rice in Bangladesh is fully irrigated and the aman rice is partly irrigated. An estimated 3,000 to 5,000 litres of water is required to produce one kilogram of rice. Recent research at IRRI has proven that using Alternate Wetting and Drying (AWD), about 15-30%, if not more, could be saved without reduction in yield. Starting from about 15 days after transplanting, irrigate until the water table goes 20 cm below the ground level. Dig a 20 cm deep hole in the rice field and install a perforated plastic pipe to monitor the level of the water table after each irrigation. Continue the practice until flowering starts. Keep 2-4 cm standing water from flowering to dough stage. This is now being valided in Bangladesh by BRRI, BADC, BMDA and othe partners. The savings of irrigation water will have impact on environment because of reduced withdrawal of ground water, reduction in burning diesel. This may also reduce arsenic contamination in rice grain and straw. |
