| Based on GIS technology,statistical methods and soil-landscape model,the article has studied the distribution characteristics of organic matter,and soil spatial -temporal variation of soil surface (0～20cm) organic matter from 1983 to 2008 for 25 years in Chang Wu,Shanxi province,loess hilly and gully region. The result of date statistics shows that the organic matter of surface is higher than other profiles. The average of organic matter content is 13.44 g·kg–1,the coefficient of variation is 25.41%;From the analysis result,the soil organic matter has a better correlation with the landscape units divided by topography and land-use type,which has a significant correlation with the topographic variables. The order of soil organic matter with different land use patterns is:woodland> grassland> garden> arable land;the order of coefficient of variation is:woodland> grassland> garden> arable land;the order of soil organic matter with different topographies and geomorphologies is: middle slope > plateau surface> ditch slope department> plateau edge > gully bottom,the order of coefficient of variation is: middle slope > gully bottom > ditch slope department > plateau edge> plateau surface; the order of soil organic matter with different soil is: dark loessial > soil loessial > laterite > river silt soil;the order of coefficient of variation is: river silt soil >soil loessial >laterite > dark loessial. It has a weaker spatial correlation in SOM1983 , but medium in SOM2008, because the interaction between structural factors and random factors according to the map of semi-variance. Compared with the year 1983, it is generally higher in year 2008. During those times, The soil organic matter is growth form 9.90 to 13.44 g·kg-1,which main reason is caused by Fertilization,cultivation measures, land-use changes(like garden land was conversed by arable land),national policy in conversion of cropland to forest and grassland to protection vegetation in slope gully,etc. |
PDF Full Text Request