摘要
该文主要从黄土地区特殊的环境条件入手，反复论证了黄土—土壤结构剖面的形成是在黄尘沉积、成壤和成岩三种过程同时同地进行而形成的现象，并详细论述了这三种过程的实质及其演变规律后认为：黄土土壤结构剖面主要来自：①在干冷时期成壤过程中形成的团粒和团块状结构，这类结构是在原先黄尘堆积时形成的黄土点棱接触支架式多孔结构的基础上多少受植物根系的固结缠绕和有机物的掺加而形成的。②在温湿时期成壤过程中形成的团粒、海绵状结构，更由于生物粘化作用的强烈进行，在腐殖质大部矿化后新形成粘粒的包裹作用下形成棱块和棱柱状等结构。③富含钙质的水在下伏缓渗层的上部滞留，并将ＣａＣＯ＿３淀积下来形成沙礓或钙板，那时孔隙全被封闭而成托水层。由此不难理解黄土土壤结构剖面构型的深入研究将对全球变化，尤其周期的气候变化及其波动，黄土高原的开发和生态环境的改善，以及成壤过程的实质等方面的研究都具有非常重大的意义。
Mainly focused on the special environmental conditions of loess area,the article takes greatlength in discussing the phenomenon that the formation of loess-soil structure profile being the co-ac-tion result contemporaneous with dust sedimentation,diagenesis and pedogensis at the same time andplance.fter a detailed study on the nature and evolution of these three processes,the article comes tothe conclusion that loess-soil structure profile generated mainly from :①The crumble and granularstructure which were formed to some extent by the tangling consolidation of vegetation roots and ad-mixture of organic materials on the basis of loess dot and arris contacting trestle porous structure de-veloped when the dust sediments piled up in the soil-forming process during dry and cold period.②Crumble ,spongy structure ,especially massive and columnar structure generated from the coating ef-fects of the newly formed clay particle after most of humus were mineralized while biologieal cohesiveaction is strongly activated .The burying condition can lower the former ratio of prosity,hence lead tothe increasement of bulk density.③The water riches in calsium perches on the upper part of underly-ing slow-seepage layer where CaCO_3 settle down and becomes what we know as lime nodule or calsiteslate,then all the pores are sealed and it turns into a water-resisting layer. From the reasons listedabove,it is obvious that the detailed studies on loess-soil structure profile is of great significanceon :Global change,especially periodical fluctuation of climate;The development of economy on loessplateau and the improvement of its ecological envirenment ;The studies on the essence of soil-formingprocess and other related fields.
出处
《水土保持学报》
CSCD
北大核心
1994年第2期1-9,共9页
Journal of Soil and Water Conservation
关键词
黄土
土壤结构
多空结构
新成土
loess dot and arris contacting trestle porcos structure soil structrue profile entisol bio-genetic clayization bio-genetic calcification
