中文摘要：

通过收集我国1980-2006年以来966个样点农田耕层土壤有机碳的实测数据,以及各样点的气温和降水数据,分析中国农田土壤有机碳变化特征,对变化的原因和发展趋势进行了探讨,对比分析了气温与降水对水稻土与旱作土固碳能力的差异,以及气温和降水对不同区域土壤有机碳的影响。结果表明：总体上我国实测点耕作表层土壤有机碳呈上升趋势,79%增幅样本主要集中在年增幅为0-3%的区间。农田土壤有机碳的含量受制于气温与降水,及水热条件的组合。20年来,全国农田土壤耕层有机碳含量的分布格局没变。农田土壤有机碳的变化,主要受人类活动的影响。土地利用方式对土壤固碳差异明显,水稻土有机碳水平明显高于旱地,水田耕层有机碳含量为旱地耕层有机碳含量的175-176%。

英文摘要：

Through collecting 966 samples of measured data of farmland topsoil organic carbon, as well as temperature and precipitation data from 1980 to 2006 of China, this paper analyzed changing characteristics of farmland soil organic carbon of China, discussed the reasons of change and development trends, and analyzed the differences of carbon sequestration ability of the temperature and rainfall on the paddy soil and dry soil, and the affection of temperature and rainfall on the soil organic carbon in different regions. The results show that farmland topsoil organic carbon of measured points presents upward trend overall, with 79% of increase samples mainly concentrated in the rise of 0-3% range. Soil organic carbon content was subject to climatic factors of temperature and precipitation, and the combination of hydrothermal conditions. Over the past 20 years, the distribution patterns of farmland topsoil organic carbon content remains unchanged. The change of farmland soil organic carbon was mainly affected by the impact of human activities. The difference of land use on soil carbon sequestration was significant, the level paddy soil organic carbon was significantly higher than the dry land, and the content of paddy topsoil organic carbon was 175%-176% of that of dry land.