退耕还林工程实施前后黄土高原地区粮食生产时空变化

Spatial and temporal changes in grain production before and after implementation of Grain for Green project in Loess Plateau region

始于1999的退耕还林工程是中国政府针对西部生态脆弱区所实施的重大生态工程。工程的实施对当地粮食生产的影响及由此而产生的政策效果是值得研究的问题。该研究利用1996年、2003年和2007年黄土高原地区分县统计数据,对中国黄土高原生态脆弱区1999年以来所实施的退耕还林工程对粮食生产能力的影响进行了分析。结果显示,从1996年到2003年,研究区粮食播种面积下降剧烈,之后有所回升,到2007年大部分县粮食播种面积下降的势头得以遏制;从1996年到2007年,研究区粮食总产量下降,粮食单产水平提高;研究区粮食单产水平远低于全国平均水平,人均粮食产量略低于全国平均水平,二者都表现出较大的年际波动性。粮食生产水平越低,其年际波动性越大。不稳定的粮食产量会强化农民的垦殖动力,不利于退耕工程实施成果的巩固。应根据各地的条件,有区别有节奏按适度规模循序渐进地推进退耕还林工程的实施,并在政策上对农民的生计进行引导和保障,以巩固退耕工程实施效果。

Grain for Green Project began in 1999 is a major ecological projects implemented by the Chinese government for the ecologically fragile areas of the Western China. Implementation of the project on local grain production and the resulting policy effect is a problem worthy of study. This paper analyzed temporal and spatial variation of grain production in the eco-fragile area of the Loess Plateau of China before and after the implementation of the Grain for Green Project using county-level statistics in 1996, 2003 and 2007. The results showed that from 1996 to 2003, the sown area of grain of the study area declined sharply, and then began to rise gradually. Downward trends of grain sown area had been checked for most counties until 2007. From 1996 to 2007, the study area＇s total grain output declined, but the level of grain yield per unit area increased. The grain yield per unit area of the study area was far lower than the national average, while per capita grain production in the study area was slightly lower than the national average, but both showed great inter-annual fluctuations. The lower the level of grain production, the greater the inter-annual fluctuations could be observed. Unstable grain production will strengthen the farmers＇ motivation, which goes against the consolidation of the results of Grain fro Green. Grain for Green project should be implemented step by step according to the local condition with an appropriate scale in study area. Further more, the livelihood of farmers should be conducted and protected in terms of policy to consolidate the project effects.