Abstract:The temporal and spatial variability of soil organic matter (SOM) contents was studied in 1980 and 2000 in Quzhou County (Hebei Province, China) ——A typical example of the alluvial regions of Huang Huai Hai Plain. Referring to the scenario of 1100 sampling points of the detail soil survey carried out in 1980, sampling point scheme was devised by combining square grid sampling points with hierarchical sampling method. In total, 124 sampling points were selected: 76 points were set by the square grid sampli...