全球变化知识资源中心

Exploiting the full potential of the realizable triple cropping system (RTCS) is one of the most effective methods for increasing land productivity, thus promoting food security. However, insufficient attention is paid to the spatial distribution of the RTCS in China. Here, a method is developed to assess the RTCS in China, considering terrain, climatic conditions, crop climatic-ecological suitability, and the spatial changes in the RTCS between 1951 and 2010. Results indicate that a decrease of 19 Mha was caused by topographic correction, while climate change increased the same area by 14 Mha. Based on crop climatic-ecological conditions, the suitability of the RTCS was indicated for 1068 counties. The boundary of the RTCS moved northward by 100-200 km in the Middle-Lower reaches of the Yangtze River, but southward by approximately 250 km in Yunnan Province. The area of the RTCS is 135 Mha distributed across 775 counties in Southern China. These findings are useful for guiding the policy of cultivated land use in Southern China. The approach can be adopted elsewhere to determine the RTCS for sustainable land use and increasing land productivity.