Conclusions
Rainfall simulation experiments were conducted to study the effects of
six measures of two tillage systems on water-based soil erosion of a
black soil hillslope during the
maize seedling stage under two rainfall intensities (50 and 100 mm
h-1) in Northeast China. The results showed that corn
seedlings can protect the surface soil from splash-erosion by reducing
the kinetic energy and changing the distribution of raindrops.
Conservation measures with mulching, including Cm, Hr, Hr+Cm, and Vr+Cm,
significantly reduced water and soil loss compared to conventional
tillage. Hr had a risk of ridge rupture, especially under heavy rainfall
conditions; and rupturing of ridges provided an excessive sediment
source and potentially triggered severe soil erosion. Mulching had an
ideal erosion-controlling capacity. In addition, mulching can mitigate
soil loss increase caused by heavy rainfall. The positive effects of
mulching were based on its strong ability to reduce splash-erosion and
runoff volume and, more importantly, on its function to decrease runoff
velocity and filter runoff sediment in. Vr further exacerbates soil
erosion and should normally be avoided. Hr+Cm showed the best
performance in all cases and should be used as an optimized tillage
measure on the black soil hillslope to restrict soil erosion at the corn
seedling stage.