Vertical Distribution Of Soil Iron Of Alnine Meadow In Northwest Sichuan

Iron is a redox substance in the wetland; its change has a very importantfunction of the indicative for the wetland environment. It is also the essential traceelement for the plant, plays an important role in life activities of theplant. The composition of the soil iron reflects the process of soil and environmentalconditions of the soil, the iron content and distribution of soil affect the levels of soilplant for iron while affecting the biological toxicity and the availability ofnutrients in the soil of heavy metals and other pollutants. And geochemical cycles of theiron in wetland soil also have important environmental significance.The results show that:(1) in the two plots, the concentration of total iron in the soilsurface was swampland blocks (9.56%)> meadow land (3.26%), the effective ironcontent of the soil surface (286.6mg/kg)>(158.89mg/kg).(2) In the meadow land andswamp block, the soil iron distribute along the soil profile as a whole showed adownward trend, but it have a varying degree of fluctuation in the middle of the soilprofile. In the meadow land, the concentration of total iron content is1.57%-3.59%.The vertical coefficient of variation is28.96%; in swamp block soil, the concentrationof total iron content is1.21%-9.56%, the vertical coefficient of variation is67.69%. In0-10cm depth of the soil profile, the total iron content is the soil block> the swampmeadow land, the iron content of the soil at the depth of10-35cm of the soil is themeadow land> the marshes block, and below35cm, between the two plots, thedifference is not significant and are into line.(3) In meadow land and swamp land, soilsavailable iron distributed along the soil profile as a whole show that first decreased andthen increased trend, and in the middle of the soil profile, there is a higher degree ofvolatility. In the meadow plots, soil available iron content is146.14mg/kg-167.1mg/kg,the vertical coefficient of variation is33.13%; in the swamp blocks, the soil availableiron content is248.03mg/kg-286.6mg/kg, the vertical coefficient of variation is 67.69%. No matter in any depth of the soil profile, the contend of soils available iron isthe swamp block’s> the meadow plot’s. Simultaneously the degree of change in themarsh lands block is greater than the meadow land’s. In two plots, the maximum of soilavailable iron is167.1mg/kg, is located at0-10cm of soil surface; the maximum of soilavailable iron is286.6mg/kg in meadow soil that is at the depth of30-40cm.(4) withinthe study area, regardless of meadow land, or swamp-block, the total iron content andthe soil available iron content have a certain relationship with soil water content、pH、soil organic matter, and the total iron also has some relevance with available iron. Dueto the impact of changes in soil moisture and vegetation, for soil total iron and soilavailable iron, the influencing factors are different, the related nature and the degree arealso different. The main factors to total iron content order as soil moisture> soil pH>soil organic matter in meadow soil; affect the marshlands block soil profile total ironcontent of the main factors for total iron content order as soil moisture order> soilorganic matter> pH value in marshland soil; the main factors for soil available ironorder as soil moisture> soil pH and soil organic matter in meadow; the main factors forsoil available iron order as soil moisture> soil organic matter and soil pH value, isequal to the correlation coefficient is equal to soil organic matter and soil pH.