Soil Taxonomy At Lower Category In A Typical Area Located At Chunhua Town Of Jiangning County Of Jiangsu Province

According to the requirement of the cooperative team of the Subject of Soil Taxonomy at lower category of China,Chunhua town of Jiangning county of Jiangsu province was chose as a typical area to study the soil taxonomy at lower category of Ustic Luvisols. In the area, the factor of landform, ground vegetation and parent material and hydrographical condition were surveyed.Several group pedons was located according to those factors. The pattern of those pedons were observed and described under the technical rule of field survey.213 pieces of soil sample for analyzing and 51 pieces of card-box soil sample were collected.According to the card-box soil sample, pedon pattern describing table and other data, 51 pieces of pedons were compared and grouped. 11 pieces of characteristic horizons,such as Anthrostagnic epipedon, Anthrostagnic mottle horizon, Anthrostagnic C horizon, Anthrostagnic plowpan, Anthrostagnic illuvial horizon,Tight yellow horizon, Ochric brown horizon,Ochric yellow horizon, Homogeneous brown horizon,Cutan brown horizon, Cutan yellow horizon, were summed up. Some important physical and chemical properties of every characteristic horizon were analysed and their varying were figured.In the control depth of soil series, the type, depth and arrangement of the characteristic horizon were chose as the standard to classify the soil series, then , 6 soil series were set up:Lingchang series, Songshancun series, Dashanao series, Qiligang series, Sanlidian series, Tangjiacun series.Through the complete analyzing of representative pedons, there are 5 diagnostic horizons, such as Ochric epipedons, Argic horizon, Claypan, Hydragric epipedon, Hydragric horizon; and 4 diagnostic characteristics, such as Anthrostagnic moisture regime, Udic soil moisture regime, Thermic soil temperature regime and Ferric property. According to those diagnostichorizons and diagnostic characteristics, the senior order of every soil series was found. Also, the soil family of every soil series was defined according to soil texture, temperature and mineral composition.