中文摘要：

通过对江苏省常熟市全市范围代表性水稻土采样并布置室内短期（20d）培育实验，研究土壤有机碳矿化过程动态，并分析其与微生物生物量碳和水溶性有机碳含量的关系。结果表明：研究区域水稻土有机碳含量变化为4．88-27．31g／kg，平均为18．07g／kg，全氮含量变化为0．58～2．84g／kg，平均为1．86g／kg；微生物生物量碳、氮及水溶性有机碳含量分别为294．0～1287．4，18．54～81．78和7．01～28．79mg／kg，且不同土属间存在显著差异（p〈O．05）；土壤呼吸强度为34．76～191．68mgCO2／（kg·d），平均为79．93mgCO2／（kg·d），不同土属间高低顺序为乌栅土〉乌黄泥土〉灰黄泥土〉白土〉黄泥土〉乌沙土；培养期内有机碳日均矿化量为10．76～65．20mgCO2／kg，平均为40．46mgCO2／kg，有机碳累计矿化量为215．25～1302．13mgCO2／kg，平均为807．20mgCO2／kg，不同土属间有机碳日均矿化量和累计矿化量变化趋势为乌栅土〉乌黄泥土〉乌沙土〉白土〉灰黄泥土〉黄泥土；研究区域水稻土有机碳矿化率为3．07％～7．58％，但不同土属间差异不显著（p〉0．05）。统计结果表明，土壤有机碳呼吸强度和日均矿化量与微生物生物量碳及水溶性有机碳之间均呈显著正线性关系，相关系数分别为0．686、0．594、0．826、0．749。

英文摘要：

With incubation tests in laboratory, the mineralization of organic carbon in typical paddy soils in Changshu,Jiangsu Province, was investigated, meanwhile, the relationship between microbial biomass carbon,dissolved organic carbon and mineralization of organic carbon was also analyzed. Results showed that the content of soil organic carbon and total nitrogen in this region were 4.88-27.31 and 0.58-2.84 g/kg, averaged in 18.07 and 1.86 g/kg respectively. The content of microbial biomass carbon, nitrogen and dissolved organic carbon were 294.0- 1 287.4,18.54-81.78 and 7.01-28.79 mg/kg respectively, and were significantly different in different soil genus. The soil respiration intensity was 34. 764191.68 mgCO2/（kg · d）, averaged in 79.93 mgCO2/（kg · d）. The sequence of respiration intensity in different soil genus was Wushan soil〉Wu-huang-ni soil〉Hui-huang-ni soil〉White soil〉Huang-ni soil〉Wu-sha soil. The daily mineralization of soil organic carbon was between 10. 76465.20 mgCO2/kg,averaged in 40. 46 mgCO2/（kg · d）. The cumulative mineralization of soil organic carbon was 215.25-1 302.13 mgCO2/kg,averaged in 807.20 mgCO2/kg,and the sequence of daily and cumulative mineralization was Wu-shan soil〉Wu-Huang-ni soil〉Wu-sha soil〉White soil〉Hui-huang-ni soil〉Huang-ni soil. The rate of soil organic carbon mineralization in this region was 3.07-7.58- and had no significant difference in different soil genus （p〉0.05）. Statistical analysis showed that there existed positive liner relationship between respiration intensity, daily mineralization of soil organic carbon and microbial biomass carbon, dissolved organic carbon, the correlative parameter were 0. 686,0. 594,0. 826,0. 749, respectively.