The influence of tillage on bulk density of the surface soil (0~20cm) was stronger than on that of the subsoil. Soil infiltration rate varied greatly with the time and tillage. The infiltration rate under conventional tillage was the highest among the treatments in the summer corn growth season, but the differences between the treatments got smaller along with the time. In terms of infiltration rate under different water tension conventional tillage was the highest and non-tillage the second, direct drillin...