Effects of different soil and water conservation tillage on runoff, sediment and soil carbon

To study effects of different tillage on soil and water conservation (SWC) and soil carbon reduction on red-soil sloping land in south China, field experiments including three tillage measures(strip intercropping, contour intercropping and clean tillage) and a check were performed on the representative area named Jiangxi Eco-science Park of SWC. The surface runoff and soil loss of each treatment were investigated from 2001-2005 and total organic carbon (TOC) and carbon pool index (CPI) of soils were tested after 5 years. The results indicated that compared with the check, surface runoff reduction rates of the three farming practices were among 21.16%~75.32%, and their sediment reduction rates were among 38.08%~80.57%. It is shown that these farming practices have great benefits to preserving water and soil and stands ranked in the descendant order of contour intercropping, strip intercropping and clean tillage. Compared with CK treatment, soil TOCs and soil CPIs of the agricultural measures were increased among 37.24%~66.34% and 35.23%~55.34%, respectively. It is shown that after 5 years, these agricultural measures have active effects on increasing soil C and stands ranked in the descendant order of strip intercropping, contour intercropping and clean tillage.