Rice being the staple diet of the Bengali people, farmers here use 75 per cent of their cultivable land for growing this crop. Since rice cultivation is water-intensive, even in the past when modern irrigation technology was not introduced, farmers used indigenous methods to irrigate their rice fields with water from rivers, canals and various other water bodies. With modern irrigation pumps now available everywhere, they use it extensively. And this practice often results in overuse of irrigation water which is wasteful, increases the farmers' production cost and pollutes environment as the fossil fuel, diesel, is mostly burnt to run their pumps. The Bangladesh Petroleum Corporation (BPC) says, 23 per cent of the diesel imported by it (BPC) worth Tk.300 billion is used to run the irrigation pumps which number around a million. And with most surface water sources drying up during the cultivation season (January to June) of the major rice crop, boro, the deep tube wells draw groundwater to irrigate the rice fields. The water table, as a result, is receding fast, which is a matter of grave concern for agriculture as well as well as the ecology. Depletion of groundwater, which is a vital source of potable water, is also a cause for concern. To get around the challenges of using irrigation water sustainably, a model called Integrated Rice Advisory System (IRAS) has been developed for the country's farmers. It has been developed by the Agro-Meteorological Information System Development Project (AMISDP) of the Department of Agriculture Extension (DAE) in collaboration with the Washington University (WU) in USA. In this model, researchers use data provided by the US National Aeronautics and Space Administration (NASA) and other satellite data to inform rice farmers all about how much water they actually need for their crop, how much water they have and how much they are using.
In the study conducted by the IRAS team completed in June 2023, advisories on the requirement of irrigation water were provided to more than 10 million farmers. Advisories can be sent to farmers through the media, both print and electronic, social media and text messages directly to the farmers' mobile phones. And the credit goes, especially to IRAS, for the idea of sending advisory in the form of text message, often customised, to the farmers. The customised text sent to a farmer to meet his particular need might be like this: you don't need to irrigate your crop, or apply half a finger of water to your field and so on. And the calculation for the overuse of irrigation water is done by comparing the actual amount of water consumed by crops (which is estimated from the satellite data) with the crops' water demand estimated from the weather data (basically precipitation forecasts for the upcoming week) supplied by the Global Forecast System (GFS) of the US National Weather Service. Faisal Hossain, professor of civil and environmental engineering at the WU and leader of IRAS and his team estimated that by implementing the programme, wastage of water in Bangladesh agriculture could be reduced by about 30 per cent, cut fuel consumption (to operate irrigation pumps) by 45 per cent and save money as government subsidy worth USD115 million annually. And the drastic cut in fuel use in agriculture means a reduction in annual carbon emission by 300,000 tons.
At the trial phase of the IRAS programme, some farmers who followed the text message advisories used 32 per cent less irrigation water than usual, hired fewer irrigation pumps that consumed less fuel, but the yield was same as before.
However, the challenge is to train the country's farmers to use the advisories properly before popularising the practice among them.
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