Study On Soil Properties And System Classification In Mountainous Area Of Southern Ningxia

Soil classification is a basic work for soil science research. It is an important way of carrying soil information, and is the basis of rational utilization, management and protection of soil resources.Through the classification the complex and unordered soil can be systematic, which contributes to managing the soil under categories. This paper was guided by soil classification, selected soil in the southern mountain area of Ningxia as the research object. Through field investigation, soil acquisition and indoor analysis, the physical and chemical properties of soil in the southern mountain area of Ningxia is studied completely and systematically, determined the soil diagnostic horizon and characteristics. Eventually, a soil classification system was established. The main results are as follows:(1) According to the physicochemical properties of 20 soil profiles taken in the six counties or cities, and the Chinese soil system classification classification system(3rd Edition), study area was divided into four diagnostic surface: mollic epipedon, umbric surface, weak surface, dry surface; two diagnosis in the surface layer: cambic horizon, clay layer; a diagnosis of the phenomenon: Mattic phenomenon; six diagnostic characteristics: quasi stone contact surface, soil moisture, soil temperature, properties of humus, humus characteristics, lime, base saturation.(2) According to the diagnostic horizon and characteristics of soil profile, 4 soil orders are retrieved: Cambosols, xerosols, Argosols, Isohumisol; 5 subclasses: cold Alfisol, ustic Cambosols, moist Isohumisol, moist Cambosols, normal arid soil; 7 great soil groups: Cold and cold leaching, Jane run Cambosols main mineral element moving is less obviously, Dark fertile soil, Clay in normal arid soil, Cold and moist soil, Simple fertile and moist soil, Normal arid soil; 8 sub categories: Stone mollic cold Alfisol, Typ hap ustic Cambosols, Ordinary dark fertile soil, Ordinary clay soil, Common cold and moist soil, ordinary Hapli udic isohumosols soils, common cold Alfisol mollic, Hapli orthid; 13 soil families: Loamy feldspar mixed calcareous cold stone cold Alfisol mollic, Loamy feldspar mixed calcareous cold typ hap ustic Cambosols, Sandy feldspar mixed type calcareous cold common dark fertile soil, Loamy siliceous mixed non acid cold typ hap ustic Cambosols, Soil feldspar mixed type calcareous cold ordinary clay, Common cold and cold wet soil of the mixed type of feldspar in soil, Soil mass silica mixed type of calcareous cold common cold and cold wet prototype soil, Sandy feldspar mixed type calcareous cold common dark fertile soil, Sandy feldspar mixed type of calcareous soil of cold and frozen plain, Soil feldspar mixed type of calcareous cold common dark cold and cold leaching soil, Sandy siliceous calcareous mixed cold typ hap ustic Cambosols, Soil and silica mixed type of calcareous cold plain normal arid soil, Soil feldspar mixed type of calcareous cold ordinary simple normal arid soil.(3) The factors of soil series classification are constituded in terms of the selected index in above study and the corresponding properties including physical and chemical index. Physical index mainly includes depth, thickness and type of specific soil layer; surface soil texture; rock debris in soil, differences of absolute content of intrusive bodies, ect. are more than 30%; soil organic carbon, CEC, calcium carbonate and salt content so on. In accordance with this standard, the study area is divided into 14 soil series: Ma Dongshan, Jiu tiaogou, Xi Ping Feng, Miao Ping, Li Baiyu, Yan Jiacha, Xiang Shui, Dong Shanpo, Pan Longpo, Da Zhuang, Xia Yuan, Xiao Kou, Ming Tai and Jiang Wa.(4) Referring soil taxonomic classification with soil genetic classification approximately, it can be seen that in most case, soil taxonomy and genetic classification show several-for-one relationship, and the same sub in soil taxonomic classification class correspond different subsets in soil genetic classification. Reference result is the emergence of a type with a larger possibility, and must not equate between the taxons in the two classification system simply.