青甘宁地区灰钙土的成土特点  

The Distribution and Soil-forming Characteristics of Sierozem in Qinghai and Gansu Provinces and Ningxia Autonomous Region of China

作　　者：胡双熙[1] 张维祥[1] 张建明[1] 吴文英 武继承 

机构地区：[1]兰州大学地理系

出　　处：《兰州大学学报（自然科学版）》1990年第3期127-136,共10页Journal of Lanzhou University(Natural Sciences)

基　　金：国家科学基金<西北干旱区(青甘宁)自然环境及其合理利用>的资助

摘　　要：灰钙土在我国青甘宁地区,分布于半干旱和干旱荒漠草原带.主要成土特点:弱腐殖质积累、弱淋溶和弱钙积化.地表呈现荒漠化孔状结皮,其上生长的地衣和苔藓积累的有机质常超出土体各发生层2～5倍,腐殖质组成中,富里酸大于胡敏酸.CaCo_3在钙积层中的积累量仅比 A 层和 C 层高2～4%,只表现出钙积化特征.土体硅铁铝比值4.6～7.8,Na_2O、MgO、CaO、K_2O 含量较高,CaSO_4淀积于 B 层和 C 层.全剖面含易溶盐,但以 BC 层和 C 层集中.粘土矿物以伊利石和绿泥石为主,占75～85%.Sierozem distributes in the arid and semiarid desert steppe zone inQinghai and Gansu Provinces and Ningxia Autonomous Region of China,Its major soil-forming characteristics are the following. The soil-forming processes are characterized by weak humification,eluviation and calcification.Cellular crust appears on the earth's surface,with a desert feature.The content of organic matter which comes fromlichenes and bryopyta growing on the surface is usually 2 to 5 timesmore than that of the underlying genetic horizons in the same profile;in the humus composition,fulvic acid is more than humic acid.The calcichorizon has only 2～4% more CaCO_3 than the A and C horizons,withonly a calcification feature.In the profile of sierozem,silica-sesquioxideratio is 4.6 to 7.8,which possesses a high contents of Na_2O, MgO,CaOand K_2O.The illuviation of CaSO_4 is found in A and C horizons.Thesoluble salts have not eluviated completely in the whole profile.Clayminerals are mainly composed of hydromicas and chlorite,occupying acontent of 75～85%.

关 键 词：灰钙土 钙积层 钙化 胡敏酸 富里酸 

分 类 号：S155.28[农业科学—土壤学]