Response of P and its correlative factors to products of Environmental Degradable Mulch Film in soil

The common plastic film mulching technology causes a series of environmental issues while it controls or increases soil temperature and maintain soil humidity to increase crop yields and improve produce. The new pattern of plastic mulch film, it´s called “Environmental Degradable Mulch Film” (EDMF), which successfully achieves degradation of appearance from pieces to powders. Therefore the effect of polyethylene powder products of EDMF on physical property and chemical property of soil becomes new hotspot of discussion. This study made use of four kinds of molecular weight to simulate polyethylene powder products of EDMF as soil additive of potted soybean, tested total P, efficient P, organic matter, acid phosphatase of soil in soybean developmental periods. The results showed that the total P content of experimental groups which added polyethylene powder products of EDMF were lower than control group, and the max decrement was 25.5%; efficient P content, organic matter content and acid phosphatase activity had no significant differences between experimental groups and control group in soil, and there were relativity among all of them. Efficient P and acid phosphatase activity, efficient P and organic matter were significant positive correlation (R=0.9982 R=0.9985); organic matter and acid phosphatase were negative correlation (R=-0.9966). The polyethylene powder products of EDMF have no significant effects on efficient P, organic matter and acid phosphatase in soil, whereas there are a little effect on speed total P consumption.