There are more windy days in spring, and greenhouses and sheds are easy to be torn or torn, causing vegetable freeze damage. Therefore, before the arrival of the spring breeze, the reinforcement of greenhouses and sheds is the key to ensure the safe production of vegetables.
First, compaction cover
Listening to the weather forecast in a timely manner and adopting appropriate countermeasures based on the forecasted wind force are the basis for preventing the danger of strong winds. In general, the north wind below the 5th level does not pose much threat to the grasshoppers and greenhouse films, but the 4th westerly wind or east wind can blow the grasshoppers. Therefore, it is necessary to cover the roof in advance according to the forecasted wind size and wind direction. The material is compacted. With the increase of temperature, even if the greenhouse does not put a floating film, the temperature in the shed can be kept above 18°C. But before there is no retreat, do not rush to remove the floating membrane, and quickly drop the floating membrane when encountering sudden gale and rainy weather, so as to avoid the grasshopper being blown by strong wind or get wet by rain.
If the westerly wind or westerly wind is blown, the floating membrane fixed on the back slope of the shed can be simply pressed on the west side of the floating membrane and not on the east side, so that even if a small amount of wind blows into the bottom of the floating membrane, a gas packet is formed. The air in the air bag will be quickly expelled, so that the floating film is tightly attached to the grasshopper, so as to prevent the strong wind from blowing the floating film and blowing the grasshopper. When the wind is blown against the east wind or east wind, the opposite pressure film method is adopted. . The same applies to the greenhouse film. A film can be pressed up at the bottom of the gable film gable to block the joint between the film and the gable to prevent the strong wind from blowing through the bottom of the film to blow the film.
The sheds equipped with roller shutters have a certain wind resistance, but their wind resistance is limited. Once the wind is too strong, the strong wind will directly tear the grass twigs when it is blown, resulting in more damage than without installation of rolls. The curtain shed is heavier, so do not rely entirely on the shutter for wind protection. When the wind is greater than 5, in order to avoid accidents, the floating membrane should be put down for wind protection.
Second, set a high pressure when the shed edge has a higher object
According to experience, if there are tall objects such as houses, trees, etc. near the arch shed, strong winds may cause cyclones or turbulence due to the obstruction of these objects, especially when these objects are in the direction of the south direction of the arch and the swirling airflow is blocked. Dropping into the shed through the entrances and exits with more gaps on the south side of the shed result in inconsistent air pressure in the sheds, which may cause the shed film to burst. It is suggested that the arch sheds with tall objects in the vicinity should increase the number of membrane ropes, tightly seal the entrances and exits of the arches, and prevent the air flow from entering.
Third, add windproof film on both sides
For the windproof of the arch shelter, the vegetable farmer can install a windproof membrane at the bottom of the east and west sides of the arch shelter. The width of the windproof membrane should be suitable from the underground side of the arched ceiling to the uppermost air outlet, for example, when the west wind blows, the vegetable farmer will be on the west side. The windproof membrane is erected so as to prevent the wind from entering the shed from the air outlet on the west side of the arch shed and preventing the wind from scratching the shed film. If the wind exceeds level 6, the arch shed will open the air outlet on the side of the leeward to ensure that the airflow in the shed is discharged, so that the windproof effect is better.
Fourth, arch reinforcement
A windproof membrane can be installed at the bottom of the east and west sides of the arch shed. The width of the windproof membrane can be from the underground side of the arch shed to the uppermost vent. For example, when the west wind is blown, the windproof membrane on the west side will be erected, so that the strong wind can be prevented from entering the shed from the vent on the west side of the arch, and the wind can be prevented from blowing through the film of the greenhouse. If the wind exceeds level 6, it is also necessary to open the vent on the leeward side of the arch shelter to ensure that the air in the shed is exhausted. For the east-west sheds, attention should be paid to strengthening the wind resistance of the shed films on both sides. First, the import and export shall be tightly closed, and secondly, the film ropes shall be installed on the films on both sides of the large greenhouse. However, it should be noted that the film on both sides of the booth has a certain angle of inclination, and the use of film ropes is not good. A wide cloth strip of about 5 cm can be used to draw diagonally on the ground anchor at a vertical angle to the film.
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