中国耕地资源的区域差异与保护问题

Regional Difference Analysis and Preservation of Cultivated Land Resources in China

采用土地整理工程手段建设基本农田,有助于实现耕地数量保护与质量提高,但必须遵循因地制宜的原则。论文根据自然地理区划和各地区的地貌特征,从分布特点、地类结构和利用水平等方面,对中国耕地资源的现状进行分析;针对自然条件和经济发展水平的区域差异,提出各地区耕地资源建设和保护的方向与重点。东部季风区应重点完善农田水利设施,改造现有中低产田,提高土地生产能力;西北干旱区不宜大规模开发,要着重发展农业节水技术,提高水资源利用率,防治土地退化;青藏高原区则应限制开垦。在土地整理与耕地资源建设中,因地制宜具体表现在生态保护、量力而行和重在效用3个方面。

Cultivated land resources are quite limited and have decreased rapidly with urbanization during the last decades in China. The amount of cultivated land reduced from - 1. 276 × 10^8 hm2 in 2000 to - 1. 217 × 10^8 hm2 at the end of 2008. The conservation of cultivated land has become a seriously concerned problem for sustainable development and food security. By means of land consolidation and rehabilitation, capital farmland construction is encouraged and will be put into practice widely in China. But owing to the diverse natural and economic conditions, capital farmland construction must take the regional difference into account. Land consolidation should be adapted to local conditions to get an expected good effect. The keystones and strategies of cultivat- ed land protection and construction should not be the same all over even in the same region. This paper analyzes the existing conditions of cultivated land resources in China in three aspects, i. e. the distribution, the land-type structure and the land-use-grade （degree of utilization）, according to the climatic zonality and the major geomorphologic features of different regions. Five profiles across the country are selected to demonstrate the spatial variations of farmland quality related with climate and land-use-grades. The analysis leads to conclusions that land consolidation in the East China monsoon regions should be focused on the development and improvement of water conservancy and irrigation systems, and the key points are to increase the productivity of the existing cropland and soil erosion control should be carried out with any new cultivation. In the Northwest arid and semiarid areas, the emphasis should be put on the application of water-saving technology and the prevention of land degeneration. However, in the Tibetan Plateau area, the newly cultivation of farmland should be restricted or regulated and the ecological protection should be a long term policy in the fragile environment. In addition, the principle of adaptation to local conditions in land consolidation should contain three aspects. The first is to protect the ecosystem as land consolidation tremendously changes the land cover especially when cultivating virgin soil. Mean- while, it is important to realize and promote the ecological effect of cultivated land as an artificial- natural complex ecosystem surrounding urban areas. The second is to set proper goals in both amount and quality for engineering projects according to the local conditions and the existing farm- land of the highest quality or land grades. The third one is to fully evaluate and improve the integrated value of cultivated land. Only when farmers, the land users, can benefit from the land, they will more cherish the land and help to prevent and avoid abuse or excessive occupation of farmland for none farming purposes. Thus, more research of land policy and consolidation techniques are needed to insure the plan of capital farmland construction in China.