Spatial variability of soil organic carbon in semi-arid zone at a county scale
The semivariograms and geo-statistical method were used to analyze the spatial variations of soil organic carbon (SOC) in Aohan Chifeng,Inner Mongolia,based on soil samples from 0-20,20-40,40-60,60-80 and 80-100 cm layers.The results showed that SOC contents ranged between 0.23 and 20.71 g · kg-1 and decreased gradually with increasing soil depth.The spatial correlations [C0/(C+C0) ratio] of SOC contents in the soil layer of 0-20 cm was 36.61% with a moderate spatial correlation,and the C0/(C+C0) ratio of SOC contents in the soil layers of 20-100 cm was <25% with a strong spatial correlation.Soil type was the major factor affecting the spatial variability of SOC content.Prevention of soil and water loss and control of soil desertification might be the effective measures to increase SOC content in the study region.