RICE, GROUNDWATER MINING AND FORGONE ENVIRONMENTAL COSTS The reason behind this excessive groundwater mining is embedded in the heavy dependence of Bangladesh on rice to feed 165 million of its populaces. Expansion of irrigated plowing based on groundwater harvesting has enabled the country to intensify rice production through crop planting in multiple seasons along with the adoption of Hybrids and high-yielding rice varieties (Shew et al., 2019). In the last three decades, a quick increase in the area of the dry season irrigated rice (boro rice) has contributed significantly to wiping hunger and attaining self-sufficiency in rice cultivation (Hossain, 2009; Bell et al., 2015; Mainuddin et al., 2014). The contribution of the boro season is around 52% of the total annual rice production in Bangladesh. Increased utilization of shallow tube-wells (STWs) for extracting groundwater from the depth of 15 to 30 meter was the actual driver behind the expansion of irrigated dry season boro paddy area (Hossain, 2009). Rice self-sufficiency in Bangladesh is obtained by foregoing environmental costs, hence, paved a major challenge to reduce the costs while keeping the pace of rice productivity uninterrupted (Basak et al., 2016; Uddin & Dhar, 2018). This tendency of sacrificing environmental cost is somewhat patronized by the policymakers and occupied strongly at the root-level by the farming communities as well. The boro rice is a water-fascinated crop, and it is tough to reduce the water use in dry season irrigation practice without sacrificing rice yield, particularly when stakeholders are ignorant of the future threats. Moreover, Bangladeshi farmers apply on an average 38% excess water than the actual requirement (Hossain et al. 2021). Water-saving modern technologies are rarely adopted by the community as a whole despite being economical and yield maximizing.
IRRIGATION DECISIONS AND WATER PRICING In reality, never does the pricing of irrigation water in Bangladesh give any economic incentive to use less water or adopt water-saving technologies. Hence traditionally, farmers keep paddy fields abundantly irrigated regardless of the crop stages, and water requirement only for mental satisfaction or soothing eyes as the marginal cost of irrigation is near zero. The irrigation system is a private domain, but the aquifers and natural water bodies in Bangladesh are open access, and water is commonly considered as public property or natural gift available free of charge or any pricing (Pandey et al., 2020). There are mainly three types of private payment systems for irrigation water between the irrigators and farmers in Bangladesh (Rahman, 2016). In all the types of payment contract, water is provided for the whole crop season on the basis of per unit area without considering the volume of water (Krupnik et al., 2015). The irrigation water market in Bangladesh is more concerned about agronomic risks, additional cost of weeding and the risk of delayed irrigation due to possible power cut, diesel crisis or pumps being out of order, rather than the environmental externalities (Mottaleb et al., 2019). It led the price of irrigation being negotiated prior to the crop season and allows farmers to keep the field flooded profligately instead of reducing water use by alternative wetting and drying practice.
IMPACTS OF IRRIGATION DECISIONS It is evident from examining the present scenario that the groundwater table is falling as the volume of water recharge is less than the withdrawal in some places. Consequently, the maximum groundwater level surpasses the suction limit of 8 meter for three months every year. Regretfully, shallow aquifers being unsustainable means access to water resource for daily use, including the availability of safe drinking water, and a basic human need denied (Kirby et al., 2013). On the other hand, the positive groundwater balance can be obtained even in the drought-prone districts simply by irrigating judicially. A calculation on the basis of the actual requirement of irrigation water by Hossain et al. (2021) showed how decision-making by the community as a whole may convert the water scarcity into a positive water balance. According to the researchers, an observed long-term average annual groundwater shortage of 0.2 billion cubic meters (BCM) could have been diverted to recharge of 0.55 BCM. Hence, the perspective says, changes in irrigation decisions can bring the ultimate solution, and the blame from the agriculture sector for destroying the environment can possibly be revoked as well. But the ignorance about the importance of groundwater and the consequent over-extraction cannot be stopped without thorough policy reforms. Otherwise, in the face of climatic vulnerabilities, if such unmindful depletion of groundwater continues regardless of the constant fall of water level, the agrarian economy may get threatened to lose sustainability.