Spatial variability of soil properties and its affecting factors at small scale

This study selected some areas in the Honghuatao town, Yichang City located in the middle reaches of Yangtze River as sample area to study the spatial variability and its affecting factors of soil properties. Several soil chemical parameters on sampling points were chosen, like alkali-hydrolyzable N (AN), available P (AP), K (AK), total organic matter content (OMC) and pH value, with geostatistical methods to explore their spatial heterogeneities. The results show that all the five indexes of soil properties display a significant correlation, (P≤0.05, 0.01) except AN and AP, pH and AP, pH and OMC. The coefficient of variability (CV) reveals that all variables have variability except available P (AP) and available K (AK). Results obtained from geostatistical analysis explain that AN, AP, AK and pH have moderate spatial variability, and OMC, which is decided by random and structural factors, has weak spatial variability. The analysis of influential factors shows that AN, AP, AK are not correlated with topography and land use types, or their correlations have not reached significant level.