Taking the field experiment

the change of gravel-mulched field soil moisture of different planting years within three days after the precipitation pulses of 7.1 and 1.9 mm was analyzed quantitatively. The results showed that soil moisture content of gravel-mulched field had a positive exponential relationship with time

and the correlation coefficient ranges from 0.9381 to 0.9873

the increase of soil moisture content showed an order as following:new gravel-mulched field >middle gravel-mulched field >old gravel-mulched field. When precipitation pulses was 7.1 mm

soil moisture content of new gravel-mulched field

middle gravel-mulched field and old gravel-mulched field increased by 42.3%

27.4% and 23.2% respectively on the third day after rainfall

and the average moisture content increased by 52.7%

52.7% and 45.5% respectively than that of bare land. When precipitation pulses was 1.9 mm

the soil moisture content increased by 22.6%

27.1% and 7.6% respectively

and the average moisture content increased by 171.8%

156.4%

and 110.3% respectively than that of bare land. When precipitation pulses was 7.1 mm and 1.9 mm

the moisture content in gravel-mulched field started to decrease in 7 days and 5 days after precipitation respectively. Both of two rainfall showed that the average soil moisture content was that new gravel-mulched field >middle gravel-mulched field >old gravel-mulched field >bare field. Compared with the bare land

gravel-mulched field can improve the utilization efficiency of the rainwater.