Research advance on optimizing annual distribution of solar and heat resources for double cropping system in the Yellow-Huaihe-Haihe Rivers plain.

Optimizing the distribution of annual solar and heat resources is an important way to improve the annual yield and resource use efficiency without increasing input for the winter wheat-summer maize of the Yellow-Huaihe-Haihe Rivers plain. During 1980s, the researchers began to explore ways to increase the efficiency utilization of solar and heat resources from the sowing/harvest adjustment, variety selection, and intensive cropping system innovation. Based on study of matching relation between crop growth and resources, a technological approach to optimize the distribution of solar and heat resources was put forward by strengthening the high photosynthetic efficiency of "C₄ maize". Then, the winter wheat and summer maize "double late" technology, winter wheat/spring maize/summer maize, winter wheat/spring maize/summer maize/autumn maize cropping systems were established, which realized high yield and high efficient utilization of resources. In this paper, we reviewed current theoretical and regulation approaches for optimizing distribution of solar and heat resources of double cropping system in the Yellow-Huaihe-Haihe Rivers plain. Then proposed a quantitative and optimal resources distribution method for double cropping system, and set up the unified quantitative indexes for resources distribution between winter wheat and summer maize, which could provide theory support for further increasing anniversary production and resource utilization efficiency of the Yellow-Huaihe-Haihe Rivers plain. [ABSTRACT FROM AUTHOR]