Rainfall infiltration

runoff and soil water redistribution were studied in farming and grass slope lands of red soil in standard runoff observation field.The results showed that:(1) Runoff ratio in farming and grass slope lands were decreased with year;Rainfall was the most important factor to affect runoff;The runoff ratio of farming land was higher than that of grass land significantly(P<0.05).(2)The infiltration ratio of farming land was lower than that of grass land;The increase of water conservation amount in soil above 60 cm had a limit in farming and grass lands.The leakage of grass land would increase to keep the higher infiltration ratio under continuous rainfall

however the infiltration ratio would decrease due to no change in its leakage and lower water conservation increasing.(3)The effect of rainfall on soil water redistribution was affected by soil initial water content and slope land utilization pattern.Rainfall made soil increase more water if the initial soil water content lower.Water content in soil above 40 cm would increase due to rainfall in farming land

while rainfall would make water content increase in soil above 90 cm in grass land