How to choose plastic film? After reading this, you will understandHow to choose plastic film? After reading this, you will understand
The plastic film has been playing since its beginning, and its role has been very obvious. The land covered by the plastic film can increase the soil temperature and maintain the humidity. It has a good effect on the growth of crops. Summer is the season for many vegetables to grow. It is very moisturizing when covered with plastic film, which is conducive to the healthy growth of crops.
In recent years, various colored agricultural films have been launched on the market. Due to the different absorption and reflection laws of different colored agricultural films on the spectrum, the effects on crop growth, weeds, pests and ground temperature are also different.
Therefore, different colors of agricultural film should be selected according to the characteristics of different crops and the planting season.
1. Colorless transparent mulch film
It is also commonly referred to as a common mulch film, with a thickness of 0.015 mm and a width of 80 to 300 cm. Its light transmittance and thermal radiance are more than 90%, and it also has a certain reflective effect.
Widely used in spring to increase temperature and store water and moisture, in addition, it can also improve soil microbial activity, which has a certain effect on improving soil and increasing soil organic matter content.
2. Black mulch
The low light transmittance can effectively prevent the evaporation of water in the soil and inhibit the growth of weeds, but the temperature increase is slower than the transparent film. The ground cover can significantly reduce the ground temperature, suppress weeds, and maintain soil humidity.
The plots with severe weeds or the cultivation of summer radishes, cabbage, autumn cucumbers, and late tomatoes in hot seasons, the best effect is to use black agricultural film.
3. Silver gray mulch
The light transmittance is about 60%, which can reflect ultraviolet rays. The ground cover has the functions of cooling, moisturizing and repelling aphids. It can increase the reflected light of the ground and is beneficial to fruit coloring.
It is suitable for preventing and curing diseases and insects and heat-resistant cultivation of vegetables, melons and tobacco in summer and autumn.
4. Blue mulch
The main feature of the blue film is good thermal insulation performance. Under weak light irradiation conditions, the light transmittance is higher than that of ordinary films. Under strong light irradiation conditions, the light transmittance is lower than ordinary films, and the thermal insulation performance is good.
It is used for rice seedling raising, with strong seedlings, many roots and a high seedling rate. Used in crops such as vegetables, peanuts and strawberries, it can inhibit the growth of black spot pathogens of cruciferous vegetables, and has obvious effects of increasing yield and improving quality. It can also be used for vegetable, cotton, peanut, strawberry, potato and other crop cover cultivation.
5. Green plastic film
Green plastic film mulch can reduce the visible light transmission of plants for vigorous light and action, while green light increases, which can inhibit the formation of weed chlorophyll, can reduce the photosynthesis of weeds under the film mulch, and achieve the purpose of inhibiting the growth of weeds.
Its warming effect on the soil is stronger than the black film, but not as good as the transparent film. Therefore, the role of green plastic film is mainly weeding, supplemented by warming.
It can be used for weeding in spring instead of black mulch. It can also promote the growth of aerial parts and improve the quality of crops such as eggplant, bell pepper and strawberry.
However, green mulch film is more expensive, easy to age, and has a shorter service life, so it can be used for ground cover on some crops with high economic value or when cultivated in facilities.
6. Black and white double-sided film
The black-and-white double-sided mulch is milky white on one side and black on the other, with a thickness of 0.02 ~ 0.025 mm. Milky white is upward, which has the effect of reflecting and cooling;
Because the effect of cooling and weeding is better than that of black mulch in high temperature in summer, it is mainly used for heat-resistant cultivation of vegetables and melons in summer and autumn. It has the functions of cooling, water retention, gloss enhancement, and weed control.
7. Red mulch
Red mulch film can stimulate crop growth more than black mulch film, and plants will use more energy for aboveground photosynthesis. The red mulch can transmit red light, and at the same time can block the transmission of other colored light that is not conducive to the growth of crops, so that the crops grow vigorously.
Practice has proved that red agricultural film can meet the needs of rice, corn, beets, etc. for red light, can make rice seedlings grow vigorously, sugar content of beets increases, carrots grow larger, leek leaves are thicker and thicker, and the harvest period is earlier.
8. Other colored mulch
In addition to the above-mentioned colored mulch, there are milky white mulch, yellow mulch, purple mulch and so on.
The heat radiation rate of the milky white film is 80 ~ 90%, which is close to the transparent film, and the light transmittance is only 40%. It has a certain inhibitory effect on weeds. It is mainly used for tile mulching, which can solve the problem of serious grass damage caused by the transparent film.
Covering the cultivated cucumber with a yellow film can promote its blooming and increase its yield by 1 to 1.5 times; covering the cultivation of celery and lettuce, the plant grows tall and the bolting is delayed; covering the dwarf lentils, the internode growth of the plant, the growth of beans is strong.
The purple film can increase spinach output, delay bolting and prolong the market season.