Water usage and productivity of Boro rice at the field level and their impacts on the sustainable groundwater irrigation in the North-West Bangladesh

Groundwater-irrigated Boro rice is produced on 83 % of the net cultivable area (NCA) in North-West (NW)region of Bangladesh. Falling groundwater levels in many parts of the region raised concerns about the sustainability of groundwater irrigation. It is generally accepted that, in the absence of a comprehensive scientific study, uncontrolled groundwater use for Boro rice cultivation leads to water wastage and low water productivity.Therefore, it is crucial to know the actual field-level water usage and, irrigation water productivity, which willhelp identifying options to sustain groundwater irrigation. This study provides a comprehensive account of theseaspects of Boro rice cultivation based on field observations at 420 farmers’ plots in 2015–16 and 2016–17seasons across seven sites in the NW region. Necessary data, including land type, soil type, rice varieties, seedingand transplanting times, grain and biomass yields pump discharge, and irrigation amount were recorded.Average water productivity was 0.67 kg m−3and 0.64 kg m−3based on total available water (rainfall plusirrigation) in the fields, 0.80 kg m−3and 0.95 kg m−3based on supplied irrigation, and 1.60 kg m−3and 1.78 kgm−3based on estimated actual crop evapotranspiration (ETc) during 2015–16 and 2016–17, respectively