摘要
以桂西北两种典型土壤为研究对象(棕色石灰土、红壤),在25℃,100%空气湿度条件下培养80 d,测定培养期间土壤释放CO2量、可溶性有机碳(DOC)和微生物量碳含量(MBC),研究桂西北土壤有机碳(SOC)矿化特征和差异。结果表明:SOC矿化在培养20 d后达到稳定。80d培养结束后,棕色石灰土SOC含量高的土壤,DOC/SOC、微生物熵以及土壤呼吸熵分别为0.21%,0.94%,0.88 g/kg.h,SOC含量低的土壤分别为0.52%,0.76%,1.21 g/kg.h;红壤SOC含量高的土壤,DOC/SOC、微生物熵以及土壤呼吸熵分别为0.76%,0.22%,5.06 g/kg.h,SOC含量低的土壤分别为1.14%,0.60%,3.29 g/kg.h。在棕色石灰土上,与SOC含量低的土壤相比,SOC含量高的土壤微生物熵大(p<0.05),而土壤呼吸熵小(p<0.05);红壤的情况与之相反。总体上,棕色石灰土CO2释放速率、累积释放量、累积释放率、土壤呼吸熵以及DOC/SOC均显著小于红壤;而微生物熵显著大于红壤。从SOC矿化角度反映了棕色石灰土有机碳较红壤稳定,这对维持SOC水平,提高土壤肥力,保持土壤结构,增加碳汇等方面具有重要作用。
Two typical soils （brown limestone soil and red soil） in northwest Guangxi were selected. The contents of released CO2, Dec and MBC wore measured during an 80-day incubation period at 25℃, 100% air humidity. The results showed that SOC mineralization was stable after twenty days＇ incubation. At the end of eighty days＇ incubation, the high SOC content of brown limestone soil＇s DOC/SOC, microbial quotient, and metabolic quotient was 0.21%, 0.94% and 0.88g/kg.h, respectively. The low SOC content of brown limestone soil was 0.52%, 0.76% and 1.2 lg/kg.h, respectively. The high SOC content of red soil＇s DOC/SOC, microbial quotient, and metabolic quotient was 0.76%, 0.22% and 5.06g/kg. h, respectively. The low SOC content of red soil was 1.14%, 0.60% and 3.29g/kg.h, respectively. Compared with the low SOC content, the high SOC content of brown limestone soil＇s microbial quotient was higher and metabolic quotient was lower, but the red soil presented a reverse trend （p〈0.05）. In general, the mineralization rate, accumulative amounts and cumulative release rote of CO2, metabolic quotient and DOC/SOC for brown limestone soil were lower than those in red soil, and microbial quotient presented a reverse trend （p〈0.05）. Compared with the red soil type, the brown limestone soil type is more stable from the perspective of organic carbon mineralization. It is suggested that brown limestone soil is beneficial to maintain SOC＇s level, improve soil fertility, keep soil structure and increase carbon sequestration.
出处
《农业现代化研究》
CSCD
北大核心
2012年第5期632-635,共4页
Research of Agricultural Modernization
基金
中国科学院知识创新重要方向项目(编号:KSCX2-YW-436)
中国科学院战略性先导科技专项(编号:XDA05070403)
国家科技支撑计划项目课题(编号:2012BAD05B03-6)
国家基金面上项目(编号:41171246)
关键词
喀斯特
棕色石灰土
红壤
有机碳矿化
karst
brown limestone soil
red soil
organic carbon mineralization
