我国农村和城市的发展都处在转型时期,对土地的需求将进一步扩展,而开发边际土地的余地已经有限,未来耕地和食物安全的形势将更趋严峻,因而保护耕地成为我国的基本国策。但实际上由于缺乏保护机制,耕地仍在继续向效益更高的其它土地用途转移。因此,保护耕地的根本大计在于建立机制。保护耕地的经济机制是提高农业的比较经济效益,耕地生态服务功能的价值实现至关重要;在政策管理机制方面,要强化政府在耕地保护中的作用,规范土地管理行为,明确独立于市场的政府土地管理目标,并以法律形式固定的规划作为实现目标的手段;城市发展要加强内涵集约度。

The rural development of China is undergoing transformation.The arable land is transforming from in support into limited.The peasant living is transforming from survival into comparatively well off.The economic institution is transforming from planning into market.The manner of land use is transforming from extensive into intensive.The rural and agriculture are transforming from exploitation into support by urbanization and industrialization.The relationship between rural and urban is transforming from difference into harmony.The agricultural economy is transforming from closed smallholder towards globalization.Therefore, demand for cropland will further increase, but the development of marginal arable land is limited.The shortage of cropland and the situation of food security will be further serious in the future.Among various factors threatening the sustainability of cropland, occupation on cropland by urbanization and industrialization is outstanding.This has made Chinese government and society heavyhearted.Therefore, the central government has paid great attention to cropland conservation and regarded it as a basic national policy.However, this basic national policy has not been implemented thoroughly in practice because the mechanisms of cropland conservation have not been established.The lower comparative benefit of agricultural land use is the major reason why cropland has continuously been occupied by urban development.Therefore the comparative benefit of agricultural land use must be raised in order to conserve cropland.The mechanisms of cropland conservation also include strengthening the role of government in cropland conservation, regulating land administrative behavior of government, identifying land administrative objects of government instead of market object, and implementing objects of government by means of land use planning in legislation manner.The development of urbanization and industrialization should be towards internal land development rather than external land expansion, and stress the intensive utilization of stock land in cities.