中文摘要：

区域土壤有机碳库、固碳潜力的估算,对全球气候变化中的碳循环研究具有重要意义.本研究基于1978—1979年全国第二次土壤普查和2007—2011年农业部＂测土配方施肥＂项目的数据,并结合大量前人调研资料和田间试验数据进行整理与比较分析.同时,采取土壤类型法估算了重庆市农田土壤碳库储量和碳密度;基于GIS分析了重庆市农田土壤碳密度的空间分布特征;对30年来各区县农田土壤碳量变化趋势进行拟合分析,估算了农田土壤固碳潜力.结果表明,土壤表层有机碳库总储量为233.54×106t,土壤有机碳密度平均值为3.08 kg·m-2;渝西南、渝东北和渝东南的农田土壤有机碳密度较高,长江干流沿岸及附近低山丘陵地区土壤有机碳密度较低;重庆市农田土壤固碳潜力约为30.82 Tg（以C计）,农田土壤单位面积固碳潜力平均值为6.71 t·hm-2.

英文摘要：

The estimation of regional soil organic carbon pool and carbon sequestration potential is significant in the study of carbon cycle in global climate change. Based on the data from the second national soil survey conducted in 1978—1979 and the project of soil testing and formulated fertilization conducted by Ministry of Agriculture in 2007—2011 and combining with the analysis of survey data and field test data,soil-type method was adopted to estimate the carbon storage and density in farmland soil in Chongqing. By applying GIS technique,the spatial distribution of carbon density of farmland soil in Chongqing was analyzed. Furthermore,fitting analysis was used to reveal the change trend of carbon storage of farmland soil in various districts and counties for the last 30 years,and to estimate the carbon sequestration potential of farmland soil. The results showed that the total storage of organic carbon in topsoil was 233.54×106t,and the average value of soil organic carbon density was 3. 08 kg·m-2; the organic carbon density of farmland soil was relatively high in southwestern,southeastern and northeastern parts of Chongqing,while it was relatively low in the regions along the Yangtze river mainstream and nearby hilly regions; the carbon sequestration potential of farmland soil in Chongqing was about 30.82 Tg C,and its average value per unit area was 6.71 t·hm-2.