土地要素部门间流动对农业环境的影响

Impact of Land Redistribution Between Farming and Non-Farming Sectors on Agricultural Environment

本文运用时间系列的省级数据,采用数理统计法和生态系统服务价值评估法分析了土地要素在农业与非农部门之间流动对我国环境可持续性的影响。分析表明:近几十年来土地要素在农业与非农部门之间的流动可从三个方面影响农业环境:首先,在粮食自给率不变的条件下,耕地数量的减少使得农地利用强度加大,而过高的农业外部投入成为一大污染源;其次,非农地向农地的转化降低耕地的总体质量,并使生态系统服务功能整体下降;再次,土地在农业与非农业部门之间的这种双向流动,即农转非和非转农促使我国粮食生产重心转向生态脆弱地区,可能导致环境隐患。据此,文章认为:单纯平衡耕地数量的政策将会给环境可持续性带来不确定性。未来的土地利用和政策必须考虑环境因素,土地要素在农业与非农业部门之间流动时的价格要能够反映农业的多功能性和正外部性。

This paper applies provincial time series data to examine the impact of land redistribution between farming and non-farming sectors on agricultural environment. Main findings show that land redistribution during the past several decades affect agricultural environment in 3 ways： first of all, given the self-sufficiency rate of grain, land redistribution from farming to non-farming sectors increases intensity of farmland use, and overused agricuhural chemicals becomes one of the most important agricultural pollution sources; secondly, land redistribution from non-farming to farming sector leads to an overall reduction of cultivated land quality and ecosystem service value ; thirdly, the mutual redistributions of land, namely from farming to non-famling sectors and from non-farming to farming sectors causes a shift of grain production gravity center from the traditional areas to ecosystem fragile areas, adding to potential environmental disasters. This suggests that the policy of simply balancing cultivated land quantity will cause instability for eco- system. Agricultural and land policies in future should more take into account environmental sustainability. Land pricing during the mutual land redistributions between farming and non-farming sectors should reflect the multi-functions and externalities of agricultural land.