Properties And Taxonomy Of Soils On GuangXi Daming Mountain

The soil properties and genetic characteristics of nine typical soils on Guangxi Darning mountain at different altitudes were investigated by field survey and lab analysis, and the soils were classified by basing on the newest Chinese soil taxonomy in this paper. The results indicate that:Soil bulk density added with deeper of soil depths, and the bulk densities of soils at mid-to-low altitudes were smaller than that at high altitudes. The content sequences of soil partical were silt>clay>sand among the mechanical composition.The soil texture were from clay loam to clay. The contents of>0.25mm soil water-stable-aggregate was higher in upper layer than that in lower layer. The contents of>0.25mm soil water-stable-aggregate in A layer was between 46.40-89.89%, while B layer was less than 60%.The contents of total organic carbon, humic acids,humic acid,fulvic acid, active organic carbon, inactive organic carbon were obviously gathered in the upper layer and increased with rising of the altitudes. The E4/E6 of humic acid was higher in the upper layer and at the high altitudes than that in lower layer and at the mid-to-low altitudes. The ratio sequences of active organic carbon in the total organic carbon and carbon library activity were A>B(E)>C. Total ferrum and dissociative ferrum were gathered in B layer, and the content of total ferrum and dissociative ferrum at the mid-to-low altitudes were higher than that at the high altitudes.The quantity sequences of three soil microorganisms were bacteria>actinomyces> fungus, and the quantity declined with increasing of soil depths. Urease and sucrase were obviously gathered in the upper layer, but catalase had no regularity. Bacteria, actinomyces, fungus, urease and sucrase had obvious relativity with soil nutrient.The soil diagnostic surface horizon in Daiming mountain was Ochric epipedon. The diagnostic subsurface horizons were Albic horizon, Argic horizon and LAC-ferric horizon. The diagnostic characteristics were soil moisture regimes, soil temperature regimes, ferric property, base saturation and lithic contact.The soils were divided into 3 Orders,4 Suborders,5 Groups and 7 Subgroups by basing on the newest Chinese soil taxonomy. The vertical zone of soils on Darning mountain was:Udic Ferrisols, Perudic Ferrisols, Orthic Primosols, Perudic Cambisols.