Analyzing the Characteristics of Cropping Intensity’s Change of Cultivated Land in China During 2010-2019

The sustained stability of the arable land replanting index is crucial to the national food security strategy. The exploration of the temporal and spatial changes in the arable land replanting index is of great significance for agricultural development and food security evaluation. This study investigates China’s arable land replanting index from 2010 to 2019 using MODIS NDVI image data, S-G filtering, and quadratic differentiation methods. The results show that there are significant spatial differences in China’s arable land replanting index, with the Huang-Huai-Hai region mainly producing double-cropping crops, the Northeast Plain and Loess Plateau mainly producing single-cropping crops, and the area south of the Yangtze River mainly producing multiple-cropping crops. Overall, China’s food production is mainly based on single-season crops. There is a gradual shift towards double-season crops from north to south, with lower replanting indices in the northwest and higher indices in the eastern provinces. The south has significantly higher indices than the north. During the study period, the arable land replanting index showed an overall upward trend. There were significant increases in the replanting index in the northeast, the Loess Plateau, and the northern Huang-Huai-Hai region. However, there was a downward trend in the southern Huang-Huai-Hai region and the middle and lower reaches of the Yangtze River. It is crucial to maintain the effective planting area of arable land in the Loess Plateau and the double-season planting area of arable land in the Huang-Huai-Hai region while also addressing the downward trend of the arable land replanting index in the middle and lower reaches of the Yangtze River to ensure food security by stabilizing the index.