去除溶解性有机质对红壤水稻土碳氮矿化的影响  

Influence on Carbon and Nitrogen Mineralization after Dissolved Organic Matter Removal in Subtropical Chinese Paddy Soils

作　　者：韩成卫[1,2] 李忠佩[1,2] 刘丽[1,2] 车玉萍[1] 

机构地区：[1]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室 [2]中国科学院研究生院,北京100039

出　　处：《中国农业科学》2007年第1期107-113,共7页Scientia Agricultura Sinica

基　　金：国家自然科学基金(40471066);国家重点基础研究发展计划"973"项目(2005CB121108)资助

摘　　要：【目的】研究溶解性有机质(DOM)对红壤水稻土碳、氮矿化作用的影响,为正确认识红壤碳、氮循环的过程机制、制订科学的养分管理措施及有效控制温室气体排放提供参考依据。【方法】采用发育于第四纪红粘土的水稻土,以旱地红壤为对照,通过室内恒温培养试验研究了去除DOM土和原土间有机碳、氮的矿化差异。【结果】去除DOM使土壤有机碳的累积矿化量在培养前期(12d)下降了6.3%～8.9%(平均7.5%),但整个培养期内仅降低3.6%～6.1%(平均5.0%),其影响不显著。去除DOM对不同土壤有机氮矿化的影响不同。3种水稻土在去除DOM后,土壤有机氮的累积矿化量显著下降,降幅为11.2%～18.3%(平均12.9%),而旱地红壤仅下降7.6%,与原土没有显著差异。【结论】DOM是土壤微生物生命活动中重要的氮素来源和有机氮矿化的原初物质,虽然只占土壤有机质的很少一部分,但在红壤水稻土有机氮的矿化中起重要作用。[Objective ] The effects of dissolved organic matter （DOM） were studied on carbon and nitrogen mineralization in subtropical Chinese paddy soils, as The pupose was to provide a firm foundation for better understanding of the mechanisms of C, N cycle, establishing scientific nutrient managements, and regulating greenhouse gas emission in soils. [Method] Incubation experiments were conducted, and chemical analysis of paddy soils was derived from Quaternary red clay. A comparison with upland red soil was made, and the difference found was in mineralization of soil organic carbon. Nitrogen was investigated between DOM removed soil and the original; [Result] Soil organic C mineralization decreased by 6.3%-8.9% with an average of 7.5% after DOM removed in the first period （12d） and only by 3.6%-6.1% with an average of 5.0% in the whole incubation period. There was not significant difference. The effects of DOM removal on the mineralization of soil organic N were different. The cumulative mineralization of soil organic N in paddy soils after DOM removal decreased significantly （11.2%-18.3%） with an average of 12.9%. Compared with paddy soils, the cumulative mineralization of red soil organic N in upland only decreased by 7.6%. [Conclusion] It was suggested that while being a small proportion of the soil OM, DOM plays a significant role in the transport and supply of nitrogen （N） to microbial population. It is the initial substrate for OM mineralization and considered to be important in the N mineralization.

关 键 词：红壤水稻土 去除溶解性有机质 碳氮矿化 

分 类 号：S153[农业科学—土壤学]