The Study Of Soil Quality Evaluate And Evolvement Mechanism Of Soil Desertification Between Agriculture And Husbandry Interlace Zone In North Of Shannxi Province

It is one of furthest graveness of land degradation and of scurviness zone of environment between agriculture and husbandry interlace zone in north of shannxi province. Soil water-erosion and wind-erosion is coexistent, land desertification is one of important restrict factor between economy persistence increase and durative development of national economy in this zone, along with great exploitation in west and construction of energy chemical industry base. Based on soil desertification between agriculture and husbandry interlace zone in north of shannxi province, on the basis of theories of landscape ecology, land resource and principle of soil genesic science, through indoor analyzing and field surveying data , the properties of soil physical and chemical characteristics and of biology are systemic analyzed about desertification soil of different type and degree, establish of soil quality index system in desertification is discussed, appraised soil quality, degraded model of soil quality is attained through soil classify and evaluate in desertification zone, achieving primary achievements and important evolves are as follows: I. Desertification soil Soil physical and chemical characteristics have great differenceThe coarse sand >0.25mm: unvegetation soil > meadow > shrubby woodland>arboreal woodland, the fine sand 0.05-0.02mm and clay: arboreal woodland > meadow = shrubby woodland>unvegetation soil; fixed dune, half fixed dune and flowing dune have average OM content are 19.40g.kg-1, 9.36g.kg-1 and 0.21g.kg-1; N and P are raised from flowing dune to fixed dune, and K is not change great, the PH in mostly profile and arrangement is slight alkalinity ; the content of CaCO3 is fixed dune> half fixed dune; the CEC is arboreal woodland>shrubby woodland and meadow >unvegetation soil; arboreal woodland , the cluster >5mm in shrubby woodland and meadow average reach 340g.kg-1; the topsoil in flowing dune has not cluster >2mm, and the cluster in 2-0.25mm which had been mensurated is likely to be sand, not the cluster in deed.II. The distributing and charact of Soil-enzyme activity in different habitation of desertification zone have great relation with vegetation type and soil texture, catalase and cane sugar enzyme activity are: arboreal woodland> meadow> shrubby woodland> unvegetation soil, alkalescent Phosphats activity is: shrubby woodland>arboreal woodland> meadow> unvegetation soil, urease activity is: arboreal woodland> shrubby woodland>meadow> unvegetation soil. The Soil-enzyme activity have best remarkable relationship with soil fertility in a whole and it is sand loam soil>sand soil.III. Status of microbe and soil basal property in different vegetation types and in different desertification phaseThe result are showed that bacteria: shrubby woodland>arboreal woodland> meadow>unvegetation soil, actinomyce and epiphyte : arboreal woodland > shrubby woodland > meadow>unvegetation soil, soil microbe and soil physical and chemical characteristics are consanguineous; they have remarkable and best remarkable minus relationship in sand with bacteria , actinomyce and epiphyte, slit and clay with bacteria, actinomyce and epiphyte have remarkable and best remarkable correctitude relationship.IV. Based on known data and production of research, putting forward index system and method of land desertification evaluate in agriculture and animal husbandry interlace zone, variational trend of soil quality index can indicate the type and degreee of land desertification and the evolutive law of soil quality, soil qulity index is gradually enhanced from flowing dune in without vegetation to fixed dene in growing arbor woodland.V. Type divisions are processed to desertification soil through employ the analytical methods of primary component. Its show that the results accord the degree , type and status of soil form and growth about desertification land.