Effects of Different Land Use Patterns on Soil Organic Carbon Loss on the Loess Slope

Slope land use pattern has a close relationship with generation of runoff and sediment as well as soil organic carbon loss.A study on the runoff,sediment and organic carbon loss was conducted in 6 runoff plots on a slope in Yangou watershed.The plots were used as bare land,harvested grassland,grassland,harvested shrub land,shrub land and Robinia pseudoacacia L.woodland respectively.The results showed that the yields of runoff and sediment were negatively correlated with the vegetation coverage under different land use patterns;the losses of soluble organic carbon along with the runoff loss followed the order of bare landharvested grasslandgrasslandharvested shrub landshrub landRobinia pseudoacacia L.woodland;the losses of soil organic carbon along with the sediment followed the order as that bare landgrasslandshrub landRobinia pseudoacacia L.woodland.It is also can be seen that most of lost soil organic carbon from the total loss coupled with the transfer of the sediment,whereas only a small part of organic carbon in the soluble form lost along with runoff.Therefore,it is suggested that the key way to control runoff,sediment yield and soil organic carbon loss is to increase the vegetation coverage on the loess slope.