Abstract:

636 soil plow layers (0-20 cm) were collected in Heilongjiang typical counties in order to evaluate black soil quality situation and evolution process from soil chemical properties. The spatial variability of soil total C, N, P and K were analyzed using geostatistics combined with geographical information system (GIS). The results showed that the semivariogram of total C, total N and total P was best described by the Gaussian model and that of total K by the exponential model. total C, total N and total P had taken on the strong spatial correlation and the spatial variability of those was influenced by structural factors. Spatial variability of total K was affected by structural factors and random factors in each 1/2, which belonged to the moderate correlation. Total C was very markedly correlated with total N (R=0.945, P<0.01). The effective minimum correlation distance was 635 km, 601.4 km, 1104.4 km and 116.1 km for total C, total N, total P and total K, respectively.