White covering film helps vegetables keep warm

News:

According to the reporter's observation, many vegetable farmers use black plastic film to cover vegetables. However, experts say that the white covering film works better because it can help keep vegetables warm.

' The use of black mulch is afraid of weeds in the shed, black mulch has weeding function, while White mulch does not. ' The reporter asked a lot of vegetable farmers, they all said so. Some vegetable farmers mistakenly believe that black light absorption is strong, which is conducive to increasing the temperature under the film.

black mulch film does have grass-proof function, but its heat preservation performance is not as good as white mulch film. Weigh the pros and cons, overwintering vegetables or covered with white mulch.

White covering film helps vegetables keep warm

first, the temperature in winter is so low that grass will not grow under the covering film, even if the grass grows, it will not grow much, which has little effect on vegetables, there is no need to lay black film because of grass prevention, and the main work in winter is to raise temperature and keep warm.

second, black plastic film is also easy to cause drastic changes in the temperature of the surface soil under the film, which is not conducive to the growth and development of vegetable roots and slow seedlings. In Shouguang, there are vegetable farmers who have done experiments. On melon vegetables, white mulch film is 5-earlier than black mulch film vegetables-In 6 days, the early output can be increased by about 30%.

The third is that the two kinds of plastic film have different effects on the ground temperature under the film. In general, the temperature under the white plastic film will be higher, be sure to hold up when using white mulch. Because the transparent film has high light transmittance, it is generally 80%-93. 8%, increase ground temperature 2- At 4℃, the soil temperature in the tillage layer changes less than that under the black plastic film in one day, which is conducive to the normal activities of soil microorganisms, vigorous growth of vegetable capillary roots, and timely absorption, conversion and transportation of various nutrients. However, the light transmittance of the black plastic film is very poor, and the light is converted into heat on the plastic film, which mainly spreads upward. After the plastic film is propped up, the heat conduction is not smooth, and the ground temperature is relatively low.