Unveiling the future water footprint of paddy cultivation: evidence from a humid tropical country

Abstract Climate-water-agriculture interactions exist in a dynamic way and present increasing challenges due to climate change effects. Water scarcity emerges as a critical problem as it may reduce agricultural output and threatening future food availability. Water resource planning has become critical to ensure sustainable agricultural development. The water footprint (WF) concept evaluates agricultural water consumption by dividing it into blue, green and grey components to provide a complete assessment of water usage for agricultural decision-making. The water needs of paddy cultivation are particularly high which makes it vulnerable to climate changes. This study aims to predict future WF of paddy in Malaysia’s main rice-growing regions (Kedah and Kelantan) considering off-season (S1) and main season (S2). LARS-WG weather generator used to produce simulated future climate variables. The estimated WF components were determined through CROPWAT and Water Footprint Assessment Manual after applying the projected climate variables. The projection indicates a rise in temperatures and irregular patterns of precipitation distribution. Until the year 2040, the projections indicate that S1 will exhibit a greater WF than S2 except for the case of Kedah during S2. All models forecast green>grey>blue for both seasons except for Kelantan in S1, where it is also green>blue>grey. Adequate rainfall can reduce irrigation demand, thus lowering the blue WF. Optimizing the frequency and amount of fertiliser application offers potential to reduce the grey WF component. These insights support future planning for climate-resilient and water-efficient paddy cultivation.