A field experiment of three treatments

i.e.

traditional cultivation without mulching(CK)

white plastic mulching(WM) and black plastic mulching(BM) was designed and performed to determine the effects of film mulching on soil temperature

water content

bulk density

and porosity and respiration rate in the 0-40 cm soil layer under Populus euramericana. Results indicated that the WM treatment had better warming effect than the BM treatment

but had no significant difference in the soil water content. In the 0-20 cm layer

the WM and BM treatments significantly increased the soil total porosity

capillary porosity and non-capillary porosity and however

the soil bulk density was visibly decreased

which was reduced by 15.44% and 9.56%

respectively. Besides

the soil respiration rate in the WM treatment had no significant difference as compared with CK

but the soil respiration rate in the BM treatment was obviously decreased. The 20-40 cm soil layer showed the variation trend similar to the 0-20 cm soil layer

while the differences among CK

WM and BM were decreased in the 20-40 cm soil layer

demonstrating that the effects of plastic film mulching on poplar weakened with the increasing of soil depth. In conclusion

the two plastic film mulching treatments significantly ameliorated the physical property of topsoil

while the black plastic mulching treatment evidently inhibited the soil respiration. Therefore

the white plastic mulching was obviously better than the black plastic mulching.