Effectiveness of soil conservation methods in preventing red soil erosion in Southern China

Rainfall, runoff (surface runoff and interflow) and soil loss were recorded from 2002 to 2005 in an experiment with four treatments on sloping red soil land in southern China. Treatments consisted of bare sloping ground (control check, CK), interplanting with soybean in spring or radish in autumn (I), level terrace (i.e., grass planted on the riser and bunds built at the edge of a bench terrace) (II), and level terraces of orchards with Bahia grass planted on the riser (III). The surface runoff and erosion in treatment II and III during the four years were low despite the occurrence of potentially erosive rains. By contrast, the CK plot had both the highest surface runoff coefficient and the highest sediment yield among all the plots. The surface runoff and soil erosion of the CK plot significantly differed from that of the treatment plots (p I > III > II, whereas their order in terms of interflow was II > III > I > CK. The effects of treatment II were excellent, indicating that level terrace (i.e., grass planted on the riser and bunds built at the edge of a bench terrace) can be an excellent practice for soil and water conservation on sloping red soil land. Soil loss in southern China can be reduced through the widespread use of this approach.