Spatial distribution of soil organic carbon of Kaoping River basin in Taiwan

The interaction among soil organic carbon (SOC), pH and soil electrical conductivity (EC) are highly related to land use and spatial distribution in the Kao-Ping River basin. Soil organic matters provide soil elements and nutrients. PH of soil determines the plant variety and land use. The level of soil salinity can be used to be the indicator of the selection of plant species. In general, when the electrical conductivity is higher than 4 ds/m, it has adverse effects on plant growth. This study aimed to investigate the spatial distribution of SOC, pH and EC in Kao-Ping River basin from the SOC of topsoil samples taken from 40 sites. The results showed the soil of Kaoping River is between neutral and alkaline. Statistically low correlation existed between SOC and pH; correlation between SOC and silt-plus-clay and negative correlation between sand and EC. It can be seen that soil texture in the vegetation areas which contains more silt and clay is higher than in the non-vegetated areas. The conductivity is lower near the upstream. It showed SOC, altitude and vegetation are closely related.