Spatial Variance of Surface Soil Organic Material Content in Yucheng, Shandong Province

Soil organic matter is very important for soil fertility.In this paper, the spatial variance of soil organic matter was studied with geostatistics method and the soil samples collected at the same sites in 2006 and 1982(Dring the Second General Soil Survey).The results showed that soil organic matter contents increased from-4.35g kg-1-32.53g kg-1 with average of 12.949g kg-1, the semi-variance function could be expressed using spheric, round, exponential, and gauss model.The reasons of raising soil organic matter were mainly focusing on fertilization and cultivation, especially the straw returning measure.