汉江与嘉陵江源区土壤团聚体分布特征及机制研究  

Study on the Distribution Characteristics and Mechanism of Soil Aggregates in the Source Area of Hanjiang River and Jialing River

作　　者：刘艳玲 庞奖励 黄春长 查小春 周亚利 王海鹏 LIU Yanling;PANG Jiangli;HUANG Chunchang;ZHA Xiaochun;ZHOU Yali;WANG Haipeng(School of Geography and Tourism,Shaanxi Normal University,Xi’an 710119)

机构地区：[1]陕西师范大学地理科学与旅游学院,西安710119

出　　处：《水土保持学报》2021年第2期235-242,共8页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41271108);国家自然科学基金重点项目(41030637)。

摘　　要：以汉江与嘉陵江源区黄土母质上发育的土壤为研究对象,通过对土壤团聚体和理化性质的试验分析和数据解析,研究了两地土壤团聚体的分布规律及发生机制。结果表明:(1)汉江源区(LJH)团聚体的R 0.25、MWD、GMD值由A层的83.73%,2.17和1.11分别降为C层的59.18%,0.40和0.26,嘉陵江源区(YJS)由A层的69.72%,1.03和0.46降为C层的56.55%,0.52和0.27,分形维数(D)则随土层深度的加深而增大,即前者的D值由A层的2.46增为C层的2.53,后者由A层的2.50增为C层的2.57,表明土壤团聚体稳定性随土层深度增大而减弱,其中>2,1~2 mm团聚体对保持土壤的稳定性具有重要贡献。(2)土壤有机质、铁铝氧化物和颗粒组成中的粉粒是促进土壤大团聚体形成并维持其稳定性的重要影响因素,而SiO 2、K 2O、黏粒、砂粒和碳酸钙在不同土壤环境中对团聚体稳定性起到截然相反的作用,即前三者在LJH剖面中对团聚体稳定性不利,在YJS剖面中反而有利于维持其稳定性,后两者促进LJH剖面团聚体形成,却破坏YJS剖面稳定性,Na 2O水溶解后则对团聚体具有分散作用。(3)汉江源区的土壤,A层团聚体稳定性强于嘉陵江源区,粉粒、有机质和铁铝氧化物为其主导因素,Bt层土体致密,通透性弱,不利形成团聚体,稳定性弱于后者,C层为母质层,两地团聚体稳定性皆较差,其不同发生层之间土体稳定性的差异要大于嘉陵江源区。The distribution and mechanism of soil aggregates in the source area of the Hanjiang river and Jialing River were studied by experimental and data analysis of soil aggregates and physic-chemical properties.The results showed that:(1)The content of aggregates of>0.25 mm(R 0.25),mean weight diameter(MWD)and geometric mean diameter(GMD)of aggregates in the source area of Hanjiang River decreased from 83.73%,2.17 and 1.11 of surface layer to 59.18%,0.40 and 0.26 of parent material layer,respectively,while those of Jialing River decreased from 69.72%,1.03 and 0.46 of surface layer to 56.55%,0.52 and 0.27 of parent material layer.While the fractal dimension(D)increased with the depth deepening,and the D of the former increased from 2.46 of surface layer to 2.53 of parent material layer,and those of the latter increased from 2.50 of surface layer to 2.57 of parent material layer,indicating that the stability of soil aggregates decreased with the increases of depth.The>2 mm and 1~2 mm aggregates had important contribution to the stability of soil.(2)Organic matter,iron and aluminum oxides and silt in particle composition were important factors to promote the formation of soil aggregates and maintain their stability,while SiO 2,K 2 O,clay,sand and calcium carbonate had the opposite effects on aggregate stability in different soil environments.In other words,the first three factors were unfavorable to the stability of aggregates in LJH profile,but are beneficial to maintain their stability in YJS profile.The last two factors promoted the formation of aggregates in LJH profile,but destroyed the stability of YJS profile.It had a dispersion effect on aggregates after Na 2 O dissolved by water.(3)In the source area of Hanjiang River,the stability of aggregates in surface layer was stronger than that in Jialing River source area,and the main factors were silt,organic matter and iron aluminum oxide.The soil mass of leaching layer was dense and weak in permeability,which was unfavorable for the formation of aggregates,and the sta

关 键 词：汉江源区 嘉陵江源区 土壤团聚体 分布特征 

分 类 号：S152.4[农业科学—土壤学]