Making pottery flowerpots and seedling pots not only destroys a large number of fields to borrow soil, but also burns coal, causing environmental pollution; The product is bulky, easy to be broken, and the manufacturing and transportation costs are high. It can't be treated after use and abandonment, which increases the environmental burden.
Plastic flowerpots and seedling pots not only have poor strength and are easy to age and crack, but also have fatal shortcomings of non-degradation and difficulty in recycling. After aging, the broken fragments remain in the soil, and even after a hundred years, it is difficult to degrade naturally, which leads to soil deterioration and a large reduction in grain, vegetables or flowers. Falling into the water will pollute the water body and affect the water quality; Incineration will produce more than ten kinds of toxic gases to pollute the atmosphere. The raw materials used to produce plastic flowerpots and seedling pots consume limited petroleum resources, and with the increase of international crude oil prices, their costs are getting higher and higher.
There are three kinds of biodegradable plastic flowerpots and seedling pots: biodegradable plastics, photodegradable plastics and polylactic acid. Starch is modified and grafted and then mixed with plastics, which is called biodegradable plastics through microbial degradation. Photodegradation of plastics is mainly to add a certain amount of photosensitizer into plastics to promote plastics to absorb more ultraviolet rays and accelerate the aging and cracking process. Tang Saizhen, chairman of China Degradable Plastics Research Association, said, "At present, the technology for degrading plastics is not mature. It can reduce pollution, but it cannot completely solve the pollution problem. " Because the first two degradable plastics can not be completely degraded, the residual plastic components will still cause great harm to the soil; The price of degradable plastics is two to three times that of ordinary plastics, and there are few real users in China. The main reason why PLA-based biodegradable materials are difficult to be widely popularized and applied in some foreign countries is that the price is too high (ten times that of ordinary plastics), which makes people discouraged and limits their use.
Paper seedling pots are also used abroad, which are mainly produced and provided by developing countries such as China. Because chemical treatment is often used in the early pulping process of paper seedling pots, not only corrosive strong alkali black liquor is discharged, but also harmful waste residue and waste gas are discharged, and the "three wastes" are seriously polluted. The main raw material for papermaking is wood, which is just a scarce resource in China. Processing a ton of pulp requires 2 cubic meters of wood; It takes at least half an acre of land and more than ten years to cultivate 2 cubic meters of wood. More importantly, the environmental damage caused by this cannot be calculated by time and money. Its consumption of human limited forest resources and serious pollution of early pulping have also been opposed by environmental experts. At present, the price of paper seedling pots is too high, and they are rarely used in China. According to the feedback from some users in Germany, this kind of seedling pot also has a fatal weakness, that is, it is easy to be deformed by moisture, and it is difficult to use in the automatic seedling production line.