context: Extremely high temperatures persist in southern China, questioning the state’s capacity to secure this year’s autumn grain, notably rice, the top staple food option. Less than two months from the harvest, a key task now is to prioritise the water supply for farmland.

Reaching the highest intensity of regional temperature (determined by the average regional temperature, its range of influence and its duration) on record, the heat wave and drought have lingered in southern China for over 60 days.

Three million ha of farmland in six provinces along the Yangtze River are affected. This is a critical period when autumn crops are highly sensitive to temperature and moisture changes: Rice has entered the heading and flowering stage, while corn is in the tasseling and silking stage. Both will determine the final output in autumn, which usually accounts for three-quarters of the state’s annual grain output. Cash crops, especially horticulture and tea, are also under threat.

The north has yet to be seriously hit by high temperatures. But it faces rising risks of pest outbreaks. Warmer weather plays a role in insect population reproduction, also helping them move to high latitudes.

Although the currently affected areas only account for around 2 percent of the total farmland for the autumn crop, regulators are wary of further expansion of the extreme conditions. 300 million in anti-disaster subsidies was sent to 13 provinces, together with teams of ag experts. Localities are responsible for building up emergency water supply facilities and farmland irrigation systems. Farming practices that can reduce water evaporation and strengthen pest controls are prioritised in ag extension efforts.