Although wheat growth is known to be sensitive to temperature, the effect of global warming on yield is uncertain, especially in a large country such as China.
Researchers have compiled dozens of experimental observations on wheat growing on heated plots in various Chinese provinces. They deduced a mean sensitivity of wheat yield to temperature change (expressed in percentage points per degree): -0,7 %/°C. The yield is most often degraded by warming, except in regions where growing-season mean temperature is low and water supply is not limiting.
The researchers also provided an estimate of this temperature sensitivity parameter using different approaches; namely, by cross-checking local agronomic models and statistical models. These three methods lead to significantly different values without being incoherent, since the researchers identified causes of divergence. For example, irrigation, precipitation and atmospheric humidity are all parameters that are difficult to control or anticipate.
The results of this study, carried out in collaboration with Peking University, could be used to improve crop models in the future.