Effects of plastic film mulching on soil moisture in winter wheat field

The effects of plastic film mulching with three methods on soil moisture content in winter wheat field were investigated under semi-arid rained conditions in the Northwest of China.The results showed that the plastic film mulching could significantly increase the moisture content of soil surface layer(0~20 cm),the soil moisture under the treatment of mulching on soil surface layer from the initial stage of wintering to the turning-green stage was 2.8 %~6.4 % higher than that of the open field.However,after jointing stage,the moisture of soil surface layer was similar among mulching and the open field treatments,the deep soil(below 20 cm)moisture of mulching was gradually lower than that of open field.From jointing to mature stage,the average moisture of open field in 20~200 cm soil layer was 2.0 % higher than that of the mulching.Compared with the average soil moisture of whole growth period in 0~200 cm under three mulching treatments,Gangu pattern was the highest,Gansu pattern was the lowest,the differences between mulching treatments were significantly smaller than those between mulching treatments and open field contrast.In spite of the high grain yield of film mulching was based on high water consumption,the soil moisture of film mulching stubble field in 0~200 cm could be fully restored to the level of the open field before autumn seeding by water compensation of fallow period.