县域土壤有机质变动及与粮食生产行为关系分析

基于土壤有机质（SOM）在土壤持续利用以及区域粮食安全的基础性作用，以曲周县为实证点，采用ARCGIS的空间分析功能对县域1980和2002年SOM进行普通Kriging法插值并获取空间分布图；以农户调查资料和Cobb—Douglas生产函数验证粮食生产行为对SOM分布的影响．结果表明：1）全县SOM平均值由1980年的8．67g／kg提高到2002年的13．75g／kg，99％耕地的SOM增加量为0．67～9．21g／kg；2）SOM空间分异的随机因素增强，人为因素的作用已经超过自然因素的作用，农户粮食生产过程中的微观选择行为日趋发挥重要作用；3）不论是县域尺度还是农户尺度，粮食生产与土壤保护始终是一组博弈行为；政府宏观引导是农户突破以经济效益为中心的粮食生产行为选择观的必要措施．

Analysis of the Relationship Between Soil Organic Matter Content Changes and Grain Production Behaviors in County Region

There is a fundamental effect to keep appropriate content of soil organic matter(SOM) aiming at sustainable soil utilization and regional food security.Taking Quzhou County as an example,the spatial distribution cases of SOM content in 1980 and 2002 were mapped through ordinary Kriging interpolation method of ARCGIS.The influence of grain production behaviors on SOM content was validated using farm household survey data and Cobb-Douglas production function.The results show that: 1) Average SOM content increased from(8.67 g/kg) in1980 to 13.75 g/kg in 2002,and the SOM increment of 99% of cultivated land was 0.67-9.21 g/kg;2) The influence of random factors on SOM spatial variability increased,and the influence of farm household behaviors was more important than that of natural factors;3) Either in county scale or in field scale,the behaviors of grain production and soil conservation are two parts of a game;government macroscopic guidance is the requisite measure of promoting soil conservation and changing primary grain production behaviors.