Shed film is a plastic agricultural film necessary for the cultivation of many greenhouse vegetables. After mulching, it can provide such a microclimate environment with good temperature, humidity and light quality for crop development, and can effectively prevent diseases and pests and reduce the impact of natural ecological disasters of enterprises, so as to improve the yield and quality of crops in China, harvest early and extend the growth cycle. However, vegetable farmers do not pay attention to protection in some agricultural operations, which is easy to accelerate the aging of plastic film and affect its use effect. So how do we prevent the film from aging too quickly?
Ways to prevent rapid aging of shed films:
First, the time of high temperature closed shed should not be too long. It is understood that long-term high-temperature closed greenhouses in greenhouses can significantly reduce the service life of plastic films in greenhouses. If the closed greenhouse is used for more than one month in the summer high temperature season, the plastic film will be seriously aged: the light transmittance will be reduced, the thermal insulation will be poor, and it will be easily damaged. Therefore, the high temperature sealing period of the summer greenhouse should not be too long, generally 15-20 days. In order to slow down the aging of the greenhouse film and ensure the good light transmittance and dripping properties of the greenhouse film in winter, the new greenhouse film is not replaced when the greenhouse is closed at high temperature, and the new greenhouse film can be replaced when the next crop of vegetables is planted after the greenhouse is closed. It can slow down the aging of the greenhouse film and ensure the light transmission and dripping of the shed film during wintering.
The second is to strictly prevent steel pipe scalding, and most of the main structural frames of the greenhouse are replaced by steel pipes. In summer, the temperature of the steel pipe is very high under strong light, so it is easy to burn plastic film. Therefore, the greenhouse skeleton, especially the steel pipe, must be wrapped with a protective layer in advance, which can be wrapped with a film or some rags. The first is to prevent the iron wire and thorns on the skeleton from scratching the greenhouse film, and the second is to prevent the high temperature of the steel pipe in summer from scalding the greenhouse film and shortening the service life.
Third, try not to spray or fumigate the greenhouse with insecticides that irritate the film. Many pesticides will damage the greenhouse film after use in the shed, that is, the spray is not careful, the pesticide sprayed on the agricultural film, especially some pesticides containing sulfur or chlorine, will damage the stability of the film. Fumigation reasonable arrangement of fumigation time, should also pay attention to reduce the use of sulfur preparations. If the greenhouse is fumigated with sulfur, the service life of the film will be greatly affected, especially frequent fumigation, which will greatly accelerate the aging speed of the film.
The fourth is to avoid contact between EVA plastic film and PVC film. Most vegetable farmers do not remove the plastic film from two different mountains when replacing the new film, which is unreasonable. If PVC film is used in the greenhouse in the previous season, EVA film is used in the greenhouse in the next season, if the two membranes are in contact, it is easy to accelerate the aging speed of the EVA film, which is extremely harmful.