南方丘陵区三种母质水耕人为土有机碳的累积特征与影响因素分析

Accumulation of Soil Organic Carbon and Their Influencing Factors of Hydragric Anthrosols in Hilly Regions of South China

本研究分析了南方丘陵区3种母质水耕人为土有机碳的累积特征与影响因素。结果表明:紫色砂页岩和第四纪红黏土母质的水耕人为土在发育过程中有机碳较易累积,在种稻初期土壤有机碳的增加主要集中在耕作层,到一定阶段后下层(耕作层以下)也明显增加;相比之下,红砂岩母质的水耕人为土在发育过程中有机碳较难累积。利用逐步回归方法得到的丘陵区水耕人为土耕作层有机碳动态变化模型表明丘陵区水耕人为土有机碳的动态变化主要受细颗粒(黏粒+细粉粒)的影响。

Three Hydragric Anthrosols chronosequences, respectively derived from purple sand shale, quaternary red clays and red sandstone in hilly regions of South China, were studied to assess the dynamic changes of soil organic carbon （SOC）. The results indicated that SOC was easily accumulated in Hydragric Anthrosols derived from purple sandstone soil and quaternary red clay soils, and mainly accumulated in anthrostagnic epipedon at the initial cultivation stage followed by subsoilsm but SOC was hardly accumulated in Hydragric Anthrosols origined from red sandstone soil. The exploratory model derived from stepwise multiple regression procedure for estimating SOC of the cultivated horizon in Hydragric Anthrosols proved that SOC accumulation were mainly affected by soil particle size composition.