The residual plastic in soil is not conducive to the exchange of soil moisture and gas, and the blockage of plastic fragments is not conducive to the normal growth and development of crops. Second, destroy the soil structure. After the plastic fragments entered the farmland, the soil structure was changed, and the soil productivity and crop yield decreased. Thirdly, however, the most serious thing is that the harmful substances produced during the decomposition of plastic residues will pollute groundwater, and improper treatment will even cause secondary pollution to the environment. Fourth, it affects the survival of microorganisms in the soil. The decomposition of plastics in soil is a long process, which will decompose and volatilize many harmful substances and affect the survival of microorganisms.
Plastics are macromolecules polymerized from monomers through addition polymerization or polycondensation reaction, with moderate deformation resistance, which is between fiber and rubber, and is composed of synthetic resins, fillers, plasticizers, stabilizers, lubricants, pigments and other additives. The main component of plastic is resin. Resin refers to a polymer compound without various additives. The word resin was originally named after the lipids secreted by animals and plants, such as rosin and shellac. Resin accounts for about 40% ~ 100% of the total weight of plastics. The basic properties of plastics mainly depend on the properties of resin, but additives also play an important role. Some plastics are basically composed of synthetic resin with little or no additives, such as plexiglass.