| Effects of the plastic film mulching(DM) and liquid-film mulching(YM)and open ground(CK)on root growth and soil environment of tobacco were studied,using flue-cured tobacco variety of NC89.The results showed: Influences of three kinds of mulching on ground temperature from 5 cm to 20 cm soil layer were all showed: DM>YM>CK,5～45 days after being transplanted.The effects of DM,s mulching on retaining water were more outstanding in 0～10 cm soil layer.The differences were no evident between DM and YM in their 10～20 cm soil layer and 20～30 cm soil layer,but water content in deep-seated(30～40 cm) soil layer for YM was higher than DM and CK.Many characters of tobacco root system were represented DM>YM>CK,including entire dry-weight of aboveground,dry-weight of roots per plant,root/shoot ratio,the number of the first lateral roots per plant,the number of the second lateral roots per plant,the first lateral root thick and bleeding intensity of basal internodes.The roots of YM were much longer than the treatments of DM and CK. |