中文摘要：

以湖南省3个国家级稻田肥力变化长期定位监测点的土壤作为研究材料，测定了不施肥、单施化肥、化肥配施有机肥等施肥处理的土壤总有机碳、水溶性有机碳、易氧化有机碳及微生物量碳的含量及其相互关系。结果显示，3个监测点化肥配施有机肥处理土壤总有机碳、易氧化有机碳、微生物量碳和水溶性有机碳的含量均显著高于不施肥的对照处理，增幅分别为12．59％。82．84％、15．33％～103．95％、35．33％～97．54％、15．89％～73．73％；易氧化有机碳、微生物量碳和水溶性有机碳占总有机碳比中的变化范围分别为49．02％～58．31％、1．93％～3．46％和0．10％～0．15％，处理间差异性不太显著，其中桃江点的微生物量碳和水溶性有机碳占总有机碳的比率显著低于其它两监测点；总有机碳、易氧化有机碳、微生物量碳及水溶性有机碳之间相关性均达到极显著水平。

英文摘要：

Soil samples from 3 long-term experiments in Xinhua, Ningxiang and Taojiang counties of Hunan Province were analyzed to investigate the effect of different fertilization treatments on the contents of soil total organic carbon （TOC）, easy oxidation organic carbon （EOOC）, microbial biomass carbon （MBC）, water-soluble organic carbon （WSOC） and the relationship among TOC, EOOC, MBC and WSOC. The results showed that： Compared to CK, NPK plus manure or straw significantly increased the contents of TOC, EOOC, MBC and DOC by 12.59%-82.84%, 15.33% -103.95%, 35.33%-97.54% and 15.89%-73.73%, respectively; The percentages of WSOC,MBC and EOOC in total organic carbon （TOC） were 49.02%-58.31%, 1.93%-3.46% and 0.10%-0.15%, respectively. There was no significant difference among the above percentages in different treatments. The proportions of MBC and WSOC in soil TOC for Taojiang site were much lower than those for Ningxiang and Xinhua sites. There were highly significant correlations among TOC, EOOC, MBC and WSOC.