黄土高原中部土地利用变化对农业发展的影响

Influences of Land Use Change on Agricultural Development in the Middle Loess Plateau

20世纪90年代以来,黄土高原土地利用因政策驱动导致的剧烈变化对农业发展产生了较大的影响。以位于黄土高原中部腹地的宝塔区和安塞县为例.利用1992—2000年的土地利用详查、变更数据、2004年开展的农户抽样调查数据以及有关的统计数据,定量分析了两区县20世纪90年代以来土地利用变化对种植业、经济林果业、林业和畜牧业发展的影响。结果表明:耕地面积持续下降导致了种植业产出总量的相对减少,且减少幅度丰年明显大于旱年;经济林果业总量随园地面积的增加一直处于快速上升趋势;而林业和牧业则表现出了与林地或草地面积增减不协同的变化趋势。林业经营活动已转变为育种、育苗、造林以及林木抚育和管理。限牧政策干扰或切断了土地利用变化与畜牧业发展之间存在的内在关系,养羊业对限牧政策极为敏感。

Driven by agricultural structure regulation and ecological de-farming policy, the land use of the Loess Plateau has tempestuously changed since 1990, and the change has a biggish influence on agricultural development. Taking Baota district and Ansai county located in the middle Loess Plateau as a study case and using the data of land use survey in 1992-2000, farmer household spot check in 2004 and statistical data, this paper quantitatively analyzed the influences of land use change on grain and fruit production, forestry and stockbreeding. As a result, the paper found：（1）The standing decrease of cultivated farm area induced the loss of grain products,and the loss of an abundant year is obviously more than that of a drought year. （2） Following the growth of garden plot area,an amount of fruit product mounted up at all times. （3） Protection forestry mainly included rearing seedling,tree-planting and forest management. （4） The inherent relation between forest-grass land change and stock raising development was severed by limited graze policy, and the policy severely restricted the development of keeping sheep in Baota district and Ansal county.