Characteristics of Oxides in Argillic Soils of Warm Tem-perate Zone in China

作     者：AISUI－LONG WEIQING－FENG 

作者机构：DepartmentofSoilScienceNorthwesternAgriculturalUniversityShaanxi712100China DepartmentofSoilScienc 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：1994年第4卷第4期

页      面：363-375页

核心收录：

学科分类：09[农学] 0903[农学-农业资源与环境] 090301[农学-土壤学] 

主　　题：free degree of Fe Mn and Al oxides warm temperate zone 

摘      要：Studies of seven typical soil profiles showed that in the argillic soils derived from loess in the warmtemperate zone of China all the oxides of Fe, Mn, Al and Si were enriched with the accumulation of clayfraction in the profiles. But owing to the influence of oxidation-reduction process the migration velocity ofFe and Mn was faster than that of clay. The free degrees of those metals were in the sequence MnFeAl,which reflected their different chemical activities in soil. In soils at the same level of development, the freedegree of iron and its activity, the free degree of Al, Alo/Alt× 100, SiO_2/R_2O_3, Sio/Sit× 100, and themagnetic susceptibility were relatively close to each other respectively. It might be considered that both thefres degrees of Fe and Al and Alo/Alt× 100 could serve as the distinctive indexes for argillic soils in warmtemperate zone. The paleoclimate corresponding to the fifth layer of paleosol (s_5) in Lnochuan, Shaanxiwas warmer and more humid than the present, and the paleoecological landscape approximated to today sbioclimatic belt between the temperate deciduous broadleaved forest and the semiarid forest *** Mossbouer spectra of the colloidal fraction (1um) in the clayified horizon of argillic dark loessialsoil, cinnamon soil, brown earth and (s_5) paleosol indicated the superparamagnetic state at room *** magnetic splitting six line spectra were observed clearly at 80 K. The results fitted with a computershowed that hematite and goethite were predominant in iron oxides and commonly existed as fine *** proportion of hematite and goethite in soil colloids varied considerably with different climates. Thehigher the temperature, the larger the proportion of hematite.