Changes In Spatio-temporal Distribution Of Multiple Cropping System In China During 1980-2010

Arable land is the basic resources and conditions of human existence. Chinese people will be less, people increasingly prominent contradiction between cultivated area dropped, China has become a major issue affect food security. With the rapid socio-economic development, industrialization and urbanization accelerating,reducing arable land in China will become the long-term trend. Under the protection of China’s food security objectives, the intensive use of arable land, spatial and temporal differences and their influence factors worthy of attention. As an important feature crop cropping system is an important manifestation of cultivated land intensive use. Since the reform and opening up, improve cropping index of arable land, food production has become an important way, and it produces food Chinese food accounted for 1/3 of the total, making China succeeded in accounting for 9% of the world’s arable land to feed 21% of the world’s population.Moreover, the increase in the level of the existing arable cropping, the land reclamation benefit ratio is better,it is because of such farmland water, soil, heat, fertilizer conditions are better, wasteland development may lead to soil erosion and other ecological problems. Difficult to see from the above background, raise the level of cropping for grain production plays a vital role, it is an important measure to ensure food security. In this context, China to explore time and space differences cropping index and its influencing factors, for the protection of national food security has a very important practical significance.This paper evaluates the spatio-temporal dynamics of potential increment multiple cropping index of China during 1980 to 2010, which can reveal the land use under the significant climate warm and the rapid economic growth since 1980 s and identify the regions with greatest potential to increase food supply. We explored PIMCI of China based on PMCI extracted by ago-meteorology data and census data-derived MCI.The results indicated that:(1) The actual cropping index of arable land in China from 1980 to 2010 to increase first drop to 159.6%from 150.9% to 151.3% and reduce distribution and the distribution of heat and water resources MCI showed the consistency of space, from north to south incremental features, abundant water, geothermal resources in southern MCI significantly higher. The main area of focus is cropping southwest of displacement trends,the National Agricultural planting zoning point of view, there is a change cropping index obvious spatial differentiation. Northern plateau region, southern hilly area, northwest oasis area in MCI increase in 30 years, have reached more than 20%, the Northeast, the Huang-Huai region, Sichuan and Shaanxi region,Qinghai-Tibet Plateau region, the Yunnan-Guizhou Plateau area relatively stable, the rate of change does not exceed 10 %, while the Yangtze River region, MCI changes in the Southern region showed dramatic volatility, the highest and lowest cropping index cropping index 30 years differ by more than 30 %. Overall,a higher degree of change in abundance of hydrothermal resources are more and more mature southern region.(2) China’s arable land potential continued to increase multiple cropping index is affected by global warming in the past 30 years, in the 1980 s the national potential cropping index was 201.1%, in the 1990 s,China’s potential arable cropping index reached 208.3%, in the past 10 years, significant improvement has occurred, but the beginning of this century continue to PMCI of 210.9%. Our potential arable cropping pattern by the major impacts of climate resources, showing significant from the southeast coast to the depth variation of the Inland Northwest, a region with two cooked cooked District Boundary Liaohe River from the northeast to southwest Taihang, Qinling way, Kawakita until the mountain range. Two crop region boundaries from three crops area along the Yangtze River Basin south of the Yangtze River southwest of Wuyi Mountain,Sichuan Basin, until southern Yunnan. The potential for multiple cropping index of 200-300% of the area,100% and 200% cropping cropping boundary by boundary to the northwest extension of the trend changed dramatically changes and fluctuations in 30 years. Three ripe area expanded significantly.(3) The overall PMCI decrease from 50.2% to 48.7% during 1980 s to 1990 s and up to 59.6% by the start of 21 st century. The changes of PIMCI show tremendous heterogeneity in China. Huang-Huai-Hai plain and Yunnan-Kweichow Plateau which belongs to non-potential region has less change over the past decades.Southeast coastal area had violent fluctuation during this period. Northwest China, Inner Mongolia and along The Great Wall region decreased significantly while Northeast China, Loess Plateau, Qinghai-Tabet Plateau changed in the opposite trend.(4) It can be increased by approximately 30% harvest area by using the existing cultivated land effectivity and closing the gap between MCI and PMCI, contributing to increasing food production for 32.2%.The high potential region mainly located at south China, Middle and lower reaches of Yangtze River, Hilly Area of South China and Qinghai-Tabet Plateau. The potential increment of crop yield in these four region reach 70% of which in China. The spatially explicit results might help agricultural policies to the appropriate regions in the case of full consideration of natural resources, technology, environment and regional economic policy and other factors.Overall, our research demonstrated that there’s been dramatic spatial shift in the multiple cropping system during the past three decades in China, which is highly correlated with the rapid economic development and dramatic climate change. Cropping levels, can reflect the intensification of land use, is an important measure to ensure food security. In this context, China to explore time and space differences cropping index and its influencing factors, for the protection of national food security has a very important practical significance. Still requires a combination of economic and social future more natural characteristics resolve cropping system temporal and spatial patterns of the impact mechanism.