Effect of Heat Resource Effectiveness Change on Rice Potential Yield in Southern China

During the rice growing season, farmers’ decisions about cropping systems and seed varieties directly affect utilization of heat resource, eventually potential yield. In this study, we used hourly accumulated temperature model to calculate available resource as well effective in southern China. We conducted a spatiotemporal analysis effectiveness during season an impact assessment on yield cereal reduction. The results showed that, period 1951–2015, generally declined area And decrease worsened most recent three decades compared with 1951–1980. A strong correlation was detected between study area. When increased by 1 °C·d, would increase 14 kg ha−1. For each percentage effectiveness, reduction rate go down 0.65%. This agro-climatological aims offer scientific basis for production China, such when plant, which choose so on.