不同土层水稻土培养条件下有机碳矿化规律研究  

Study on Characters of Soil Organic Carbon Mineralization in Different Layers of Paddy Soil under the Condition of Incubation

作　　者：葛序娟 潘剑君[1] 尹正宇 邬建红[1] 周志文[1] 王恒钦 于东升[3] 

机构地区：[1]南京农业大学资源与环境科学学院,江苏南京210095 [2]南京农业大学公共管理学院,江苏南京210095 [3]中国科学院南京土壤研究所,江苏南京210008

出　　处：《土壤通报》2015年第3期570-577,共8页Chinese Journal of Soil Science

基　　金：中国科学院战略性先导科技专项课题(XDA0505050703);江苏高校优势学科建设工程资助项目(PAPD)资助

摘　　要：以湖南省桃源县水稻土为研究对象,基于土壤有机碳三库一级动力学理论,从垂直变化角度研究水稻土总有机碳(Ct)、活性碳(Ca)、缓效性碳(Cs)、惰性碳(Cp)的含量及有机碳矿化特征的相关规律。研究结果表明:1总有机碳、活性碳、缓效性碳、惰性碳含量分别与土层深度成负相关,相关系数分别为0.8431、0.8516、0.8320、0.7734(P【0.01),土层越深活性碳占总有机碳比例越小,惰性碳占总有机碳比例越大。2按照CO2-C释放速率变化程度,将矿化曲线划分为快速矿化(平均约7.94 d)、缓慢矿化(平均约28 d)和平衡矿化三个阶段,其中快速矿化阶段主要为活性碳矿化。3土壤有机碳矿化速率、累积矿化量、矿化比例等都随土层加深而减小,但30~60 cm土层有机碳总量大,其有机碳矿化总量的变化对1 m深有机碳矿化总量变化的影响大。4偏相关分析表明不同土层土壤有机碳各组分含量、有机碳矿化总量与土壤全氮含量和土壤p H相关,即土壤性质影响有机碳矿化特征。由此得出,深层土壤有机碳也参与全球碳循环,并且全氮含量和p H会影响深层碳库成为碳源或是碳汇,在研究全球碳循环时应给予充分重视。Based on the first-order kinetic equation, the contents of total organic carbon(Ct), active carbon pool(Ca),slow carbon pool(Cs), passive carbon pool(Cp) of the soil samples collected from Taoyuan County, Hunan Province were estimated, meanwhile, the organic carbon turnover characters were analyzed from the perspective of the vertical change on the profile of paddy soil. The results showed that: 1 The contents of Ct, Ca, Cs, Cp were negatively related to sampling depth, with the correlation coefficients of 0.8431, 0.8516, 0.8320, 0.7734(P < 0.01), respectively. The percentage of active pool decreased with the increase of soil depth, while that of passive pool increased. 2 According to the degree of CO2-C release rate change, the mineralization curve could be divided into fast mineralization stage(about 7.94 d on average), slow mineralization stage(about 28 d on average) and equilibrium stage. The fast mineralization stage could be considered as the stage of active pool mineralization. 3 With the increase of sampling depth, there was a downward trend in organic carbon mineralization rate, cumulative organic carbon mineralization amount, ratio of mineralized organic carbon. The change of organic carbon mineralization amount of soil(30 ~ 60 cm)had a great effect on the change of organic carbon mineralization amount of the whole profile due to the huge organic carbon storage with a thick soil layer. 4 Partial correlation analysis indicated that three pools of soil organic carbon and organic mineralization amount had a significant correlation with soil total nitrogen content and p H, namely soil properties had a significant effect on soil organic carbon mineralization characters. Therefore, the findings in this study implied that organic carbon in deep soil should be taken seriously when the global carbon cycle was studied, and the content of total nitrogen and p H would affect the source or sink of soil organic carbon in deep layers, which was also gave careful attention.

关 键 词：土壤有机碳 碳库 三库周转 剖面 

分 类 号：S153.6[农业科学—土壤学]