Research Of Soil Taxonomy And Vertical Zonality Of The Mountain Soils In Jiangxi Province

For quantitative classification of the mountain soils of Jiangxi province, four mountains with different latitude and longitude were used as researched objects. Eighteen representative soil profiles were collected from different mountains of Jiangxi province. Environmental factors of mountain soils were well described during the investigation. This paper deals with the soil-forming factors and characters of mountain soils of Jiangxi province. According to the “ Keys to the Chinese Soil Taxonomy(3rd edition)”, diagnostic horizons, diagnostic characteristics and attribution in Chinese soil taxonomic classification of eighteen mountain soil profiles were distributed vertically.The main results and conclusions obtained in the study were as follows:(1)The eighteen mountain soils under the study varied regularly with the increase of the elevation. With the rise of elevation, the average rainfall, soil organic matter and cation exchange capacity increased while the temperature and clay in the soil reduced. Humic property appeared above 850 meters. Most of mountain soils in Jiangxi province had ferric property and alic evidence. Soil organic matter varied from different vertical vegetation zonation and hydrothermal conditions. Owing to the different latitude and elevation, the content of total iron were signification different. There was obviously difference in the soil thickness, owing to the complex terrain.(2)According to the formation conditions of the mountain soils and the analysis of existing soil data, the main soil-forming processes were iron and aluminum riching, cambic soil layer development, humification and sliming and so on. According to the “ Keys to the Chinese Soil Taxonomy(3rd edition)”, nine diagnostic characteristics and five diagnostic horizons were characterized. The diagnostic horizons of mountain soils were umbric epipedon, LAC-ferric horizon, ochric epipedon argic horizon and cambic horizon. The diagnostic characteristics of mountain soils were lithic contact, paralithic contact, udic/perudic soil moisture regime, mesic/thermic soil temperature regime, ferric property, humic property, allitic property, alic evidence and dystric/dystrophic base saturation. Types of mountain soils were classified. So there were three orders(Ferrosols, Argosols, Cambosols), five suborders, nine groups and twelve subgroups in total.(3)The research result of the effect of the vertical zonality of mountains and the latitude differences of mountains shows that: With the rise of latitude, the vertical zonality of the soils became simple and the order reduced. The vertical distribution of soils which belong to the same subgroup reduced with the rise of latitude. The results of soil taxonomy and genetic classification resembled each other somewhat in general structure.