江西兴国县农田土壤固碳潜力20a变化研究

Change in Carbon Sequestration Potential of Cropland Soil for 20 Years in Xingguo County of Jiangxi, China

通过GIS技术，采集38个农田土壤样品，研究了江西兴国县农田土壤有机碳变化量的空间分布特征．结果表明，20a来，兴国县农田土壤中土壤有机碳增加的面积为621．3km^2，减少的面积为38．4km^2，增幅主要在0～5g／k和5～10g／k；千枚岩、花岗岩、红砂岩、第四纪红粘土和紫色砂页岩发育的土壤中有机碳变化量分布的面积分别为361．7km^2、144．7km^2、76.5km^2、48．7km^2和18．0km^2，海拔在300m以下、300—500m、500～800m和800m以上的土壤中有机碳变化量分布的面积分别为358．9km^2、200．2km^2、62．9km^2、28．0km^2．多元回归分析显示，20a来土壤有机碳变化量和初始含量旱负相关关系．土壤有机碳变化量和海拔、粘粒含虽旱正相关关系．

Based on GIS technique, 38 samples of cropland soil were collected in Xingguo County, and the variable temporal and spatial characteristics of cropland soil organic carbon （ SOC ） were studied. The results indicated that the area of SOC increase after 20 years was 621.3 km^2 and the increase was 0 - 5 g/kg and 5 - 10 g/kg, but that of decrease was 38.4 km^2. The areas of SOC changes in soils derived from phyllite, granite, red sandstone, Quaternary red clay and purple shale were 361.7 km^2 , 144, 7 km^2 , 76.5 km^2, 48.7 km^2 and 27.8 km^2, respectively. The areas of SOC changes in soils with elevations below 300 m, 300 - 500m, 500 - 800m and above 800 m were 358.9 km^2, 200.2 km^2, 62.9 km^2 and 28.0 km^2, respectively. Multiple linear regression analysis revealed that the changes in SOC after 20 years were negatively related to the initial SOC content and positively related to elevation and clay content. Fig 1, Tab 2, Ref 15 .