Rice (Oryza sativa L.) is a major crop, providing food for billions of people globally. However, rice yield and cultivation is less water productive, requiring approximately 2,500 litres of water per kilogram of polished grain produced (Bouman, 2009).

Irrigated rice consumes about 34%-43% of the total water used for irrigation globally, partly to maintain productivity and control weeds. In Thailand, the irrigation system covers only 22% of agricultural land, whereas the large lowland rain-fed area depends on annual rainfall. If Thailand’s maximum temperature is increased by 1%, half of the rice yield may risk crop loss.

By 2050, the rainfed lowland rice will be shrinking by half if there is no significant improvement in heat and drought tolerance. A million-dollar question is whether rice can become more water-saving and remains productive under restricted irrigation system and global warming.