Genetic characteristics and taxonomy of soils in hilly regions of central-south Hunan province

This paper deals mainly with soil-forming factors and characteristics of soil in hilly regions of central-south Hunan province through investigating eleven soil profiles.The results showed that the main soil texture was clay,which showed obvious leaching phenomenon and strong viscidity.The soil profiles were characterized by high degree of iron segregation and low activity of iron oxides,which were in the process of moderate iron-accumulation.According to the Chinese Soil Taxonomy Index(the third edition),diagnostic horizons and diagnostic characteristics were characterized and the attribution of these soil profiles in soil taxonomic classification was determined.Soil profiles 04,22 and 23 belong to red soil in soil genetic classification and Typic Hiweatheri-Udic Ferrosols in soil taxonomy,soil profiles 07 and 13 belong to red soil in soil genetic classification and Plinthic-Hapli-Udic Ferrosols in soil taxonomy,soil profile 19 belongs to garden soil in soil genetic classification and Mottlic Fimi-Orthic Anthrosols in soil taxonomy,soil profile 20 belongs to purple soil in soil genetic classification and Dystric Purpli-Orthic Primosols in soil taxonomy,soil profile 21 belongs to Regosols in soil genetic classification and Typic Udi-Orthic Primosols in soil taxonomy,soil profile 01 belongs to limestone soil in soil genetic classification and Typic Carbonati-Udic Cambosols in soil taxonomy,and soil profiles 16 and 17 belong to purple soil in soil genetic classification and Mottlic Purpli-Udic Cambosols in soil taxonomy.