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以西南大学农业部紫色土生态环境重点野外科学观测试验站试验田为研究对象,探讨了土壤有机碳(soil organiccarbon,SOC)、易氧化有机碳(readily oxidized carbon,ROC)、可溶性有机碳(dissolved organic carbon,DOC)和微生物生物量碳(microbial biomass carbon,MBC)的季节变化。结果表明,在油菜生长季,紫色水稻土SOC、ROC及MBC含量具有相似的季节变化特征,表现为在油菜生长初期和末期含量高,而在生长中期含量低;三者的含量均在生长末期达到最高,分别为16.20g.kg-1、3.58 g.kg-1及309.70 mg.kg-1.DOC含量的季节变化模态为单峰型,在植物生长中期达到最高值37.64 mg.kg-1.各活性有机碳组分的分配比例与其含量的季节变化趋势大致相同,ROC、DOC分配比例以及微生物商的季节变化范围分别为15.49%～23.93%、0.11%～0.32%和1.44%～2.06%.SOC及ROC含量主要取决于地下5 cm处温度、土壤N含量及pH值,MBC含量的主要影响因子为地下5 cm处温度、根系生物量及根系C、N含量,DOC含量主要受土壤水分含量的限制.
In this paper, the experimental field of key field observation station for purple soil ecological environment of Ministry of Agriculture of Southwest University was studied to investigate the effects of soil organic carbon (SOC), readily oxidizable carbon (ROC), dissolved organic carbon carbon, DOC) and microbial biomass carbon (MBC). The results showed that the contents of SOC, ROC and MBC in purple paddy soil during the rape growing season were similar to those in the rapeseed. The content of rape was high in the early and late rape and low in the middle growing stage. Reaching the highest, which were 16.20g.kg-1, 3.58g.kg-1 and 309.70 mg.kg-1, respectively. The seasonal variation of DOC content was unimodal and reached the highest in the middle stage of plant growth 37.64 mg.kg- 1. The distribution of each active organic carbon component is roughly the same as the seasonal variation of its content. The distribution of ROC and DOC and the seasonal variation range of microbial quotient range from 15.49% to 23.93%, from 0.11% to 0.32% and from 1.44% to 2.06 %. The contents of SOC and ROC mainly depend on the temperature at 5 cm underground, the soil N content and pH value. The main influencing factors of MBC content are the temperature at 5 cm underground, the root biomass and C and N contents in roots, and the DOC content is mainly affected by soil Moisture content limits.