Wheat yield was generally negatively correlated with precipitation in southern China, was insignificantly correlated with precipitation in northern China (Fig. 3).
Wheat yield was positively correlated with SRD for winter wheat in eastern China including Zone II and Zone III, and for spring wheat in northwestern China including Zone IV and Zone VI (Fig. 3).However it was negatively correlated with SRD for winter wheat in Zone I and Zone V, as well as for spring wheat in high altitude Zone VII.