【作者】 成丽；

【导师】 方天堃； 于法稳；

【作者基本信息】 沈阳农业大学 ， 农业经济管理， 2009， 博士

【摘要】 近年来,随着科技的飞速进步和生产力的迅猛发展,人类创造了前所未有的物质财富,加速了人类社会经济的发展进程。然而,同时也出现了世界性的资源枯竭、能源危机和生态环境恶化等一系列问题。这些全球性的重大问题,严重地阻碍着人类社会经济的可持续发展,继而威胁着全人类的未来生存与发展。1992年6月在巴西召开了联合国环境与发展大会之后,人类开始关注地球生态系统平衡和资源合理利用等问题。耕地是人类社会存在和发展的基础支撑资源,能否实现其可持续利用是直接关系到可持续发展战略的重大问题。中国的耕地资源安全形势十分严峻。根据2000年第五次人口普查结果,全国总人口为12.95亿人,全国平均人口密度为132人/平方公里,人均耕地为0.093公顷,而世界人均耕地面积为0.25公顷,中国人均耕地面积不足世界平均水平的40%,不到俄罗斯的1/6,美国的1/6,加拿大的1/15,印度的1/2(渠俊峰等,2007)。据研究,预计到2010年,全国耕地面积总量增减相抵之后将净减少6.45×10~5公顷;2020～2030年人均耕地面积将下降到0.08公顷(陈百明等,2000)。同时,中国的粮食问题成为国际社会广泛关注的热点问题之一。在工业化、城市化进程不断推进的过程中,耕地非农化的现象日趋严峻,粮食生产所需要的耕地资源问题将更加凸显。在全球一体化背景下,中国农产品参与国际竞争的能力不断增强,越来越多地走向国际市场。粮食贸易,包括区域间的粮食流动,自古以来就存在,但从20世纪90年代初人们才认识到这种“镶嵌”在粮食贸易中的自然资源的流动。以这些农产品(主要是粮食产品)为载体的虚拟耕地贸易也越来越多,直接影响到耕地资源的可持续利用。论文在分析虚拟耕地概念及农产品虚拟耕地含量匡算理论与方法的基础上,以粮食主产区为例,运用耕地压力数据分析了虚拟耕地贸易量与耕地压力的关系,进一步描述粮食对外贸易与耕地可持续利用的关系,构建全球化背景下中国地资源安全新战略,对实现中国耕地安全与粮食安全以及社会经济发展都具有战略意义。论文的主要研究结论如下:第一,新中国建国以来到1995年,中国耕地资源数量变化不大,从1996年开始,中国耕地资源数量呈明显的持续减少趋势。中国优质耕地比重低,坡耕地数量多;土壤养分缺乏严重;水土流失严重,加剧土壤肥力下降;耕地污染日趋严重。通过建立耕地压力指数模型得出,改革开放以来,中国耕地压力呈波浪式降低趋势,但是有些年份,耕地压力指数很大,说明当前中国耕地压力十分明显。第二,改革开放以来,中国总体上呈现为粮食净进口国家。最高年净进口量为2004年的2484万吨,最高年净出口为1993年的622万吨。净进出口变幅超过3000万吨。粮食对外贸易主要集中于大米、玉米、小麦和大豆四种,其中,小麦和大豆是中国主要的进口品种,大米和玉米则是主要的出口品种。第三,中国虚拟耕地贸易一直保持较大逆差,改革开放以来,除个别年份以外,虚拟耕地贸易均表现为净进口状态,虚拟耕地净进口量从1978年的415.72万公顷增加到2006年的1531.75万公顷,年均增长4.77%。粮食进口,同时伴随的虚拟耕地资源的进口对缓解粮食生产波动对粮食安全的压力,对于缓解国内耕地资源压力和维护生态环境的可持续发展,具有重要的现实意义。第四,中国耕地压力状况与虚拟耕地净进口、人均耕地面积和人均粮食产量呈负相关,与人均GDP和粮食播种面积占农作物播种面积的比重呈正相关。也就是说,粮食进口对缓解耕地压力、促进耕地可持续具有显著的正向作用。虚拟耕地战略不仅适用于国家间,同样适用于国内省级区域间,中国幅员辽阔,各地区农业自然资源禀赋不同,粮食品种及其生产效益区域差异大。从长期看,利用虚拟耕地战略,发挥各地比较优势,调整粮食品种结构,加强粮食主产区建设。目前国内的“北粮南运”,其隐藏在粮食流动中的虚拟耕地流动使耕地资源问题通过经济条件弥补,开阔了区域耕地资源管理和耕地资源配置的视野,成为保障耕地资源以及粮食安全的有效工具。第五,根据预测得出,2010年和2020年中国粮食供需缺口分别是2955万吨和3699万吨,粮食自给率分别是94.82%和94.10%,按照95%左右的粮食自给率标准,2010和2020年中国粮食安全基本上是有保障的。同时,伴随粮食进口的虚拟耕地贸易同样呈现为净进口状态,分别将达到6044千公顷和6936千公顷。总的说来,虚拟耕地贸易能够在一定程度上改善中国耕地资源压力状况,有助于实现中国的粮食和耕地的双重安全。在上述分析的基础上,本文提出粮食对外贸易能够在一定程度上有助于实现耕地可持续利用。并针对目前的耕地可持续利用的现状提出了相应的对策建议。更多还原

【Abstract】 In recent years, with the rapid development of scientific technology and productive forces, mankind has created unprecedented material wealth and accelerated the human socio-economic development process. However, there have also been a series of worldwide problems such as resource depletion, energy crisis and ecological environment deterioration. These problems can seriously hamper sustainable development of human socio-economy, and then threaten the future survival and development of all mankind. Since Conference on Environment and Development in the United Nations was held in June 1992 in Brazil, mankind has begun to pay attention to the balance of worldwide ecosystem and rational utilization of resources.Cultivated land is the basic resource of existence and development of human society. Whether we can realize the sustainable utilization of cultivated land is a major problem which impacts overall sustainable development. Cultivated land resources are under the extremely condition in China. According to the fifth census in 2000, China has a population of 1295 million, the national average population density is 132 people per km~2 and cultivated land area per capita is 0.093 hectares, compared with 0.25 hectares of the world. China’s cultivated land per capita is 40 percent less than that of the world average, one-sixth than Russia and USA, one-fifteenth than Canada, half than India (Qu Junfeng etc., 2007). On estimation, cultivated land area will decrease by 6.45×10~5 hectares by 2010. Cultivated land area per capita will drop to 0.08 hectares from 2020 to 2030 (Chen Baiming, etc., 2000).At the same time, China’s grain problem has become one of the hot topic of widespread concern in the international community. With the continuously implementation of the urbanization and the industrialization, cultivated land has been occupied and transformed from grain production uses to economic construction. Therefore, it’s crucial to maintain the sustainable utilization of cultivated land resources. Under the circumstances of global integration, China is playing a more and more important role in international agricultural products trade. Grain trade, including inter-regional grain flows, has existed since ancient times. However, people haven’t realized natural resources flow underlined in the grain trade until the 1990s. With these agricultural products (mainly grain products) as the carrier, the virtual cultivated land has greatly increased and has a direct impact on the sustainable utilization of cultivated land resources.On the basis of the concept of virtual cultivated land and theories and methods of virtual cultivated land contents of agricultural products, this paper analyzed the relations between cultivated land pressure and virtual cultivated land trade as an example of main grain production regions. Thus it analyzed the relations between grain foreign trade and sustainable utilization of cultivated land and constructed a new strategy for China’s cultivated land resources security under the circumstance of globalization, which is of strategic significance to realizing China’s food security and socio-economic development.The main conclusions of the paper are shown as follows:First, since the foundation of new China to 1995, the quantity of cultivated land resources in China hardly changed, but the quantity was in obvious decreasing trend. China has low proportion of good cultivated land and high proportion of sloping land; seriously lack of soil nutrients; serious soil erosion, deteriorating soil fertility; worsening cultivated land pollution. Through the establishment of the model of cultivated land pressure index, China’s cultivated land pressure has turned out a wavy style trend since reform and opening up, but in some years the pressure index was very huge, which illustrated cultivated land is under very obvious pressure in China.Secondly, since the reform and opening up, China has turned out a net grain import county. The highest of annual net import was 24,840,000 tons in 2004 and the highest of annual net export was 6,220,000 tons in 1993. Products of grain foreign trade are mainly rice, corn, wheat and soybeans. Among these, wheat and soybeans are China’s major import varieties, and rice and maize are the main export varieties.Third, China has maintained a larger trade deficit in virtual cultivated land. Since the reform and opening, with the exception of individual years, the virtual cultivated land trade showed a net import status, which grew from 4,157,200 hectares in 1978 to 15,317,500 hectares in 2006 with an average annual increase of 4.77 percent. Grain import, simultaneously accompanied by the virtual cultivated land resources has important practical significance to easing security pressure of the grain and cultivated land and preserving sustainable development of the ecological environment.Fourth, the pressure of China’s cultivated land has negative relations with net imports of virtual cultivated land, cultivated land area per capita and grain output per capita, and has positive relations with GDP per capita and the proportion of sown area of grain crops in that of agricultural crops. In other words, grain imports have alleviated pressure of cultivated land and promoted sustainable utilization of cultivated land. Virtual cultivated land strategy applies not only to inter-countries but also domestic inter-provincial regions. China is a vast country. There are different endowments of natural agriculture resources and different grain varieties and their production revenue in different areas. In the long term, with the use of virtual cultivated land strategy, we can play the comparative advantages, adjust the structure of grain varieties and enhance the construction of major grain production regions. As for current "north to south of food", virtual cultivated land flow hidden in the grain flow opened the perspective of regional cultivated land management and cultivated land resource allocation, which has become an effective tool of guarantee the security of cultivated land resources and food.Fifth, on estimation, China’s grain supply and demand gap respectively comes to 29.55 million tons and 36.99 million tons in 2010 and 2020, with the grain self-sufficiency rate of 94.82 percent and 94.10 percent. Based on the standard of 95 percent of grain self-sufficiency, China’s grain security is probable in 2010 and 2020. At the same time, accompanied by grain import, virtual cultivated land trade also turns out net import, which respectively reaches 6,044,000 hectares and 6,936,000 hectares in 2010 and 2020. Generally, virtual cultivated land trade can improve the conditions of the pressure of China’s cultivated land resources to some extent and contribute to the realization of China’s double security of food and cultivated land.In the above analysis, this paper concluded that grain foreign trade can contribute to the realization of sustainable utilization of cultivated land to some extent and put forward some countermeasures of realizing sustainable utilization of cultivated land resources.更多还原