First, increase the transparency of the film
When building a shed, choose a light-free film with good transparency. After snow, clean the snow on the shed film. Regularly cleaning the dust on the shed film can enhance the light and increase the temperature of the shed.
Second, timely repair holes in the shed film
Carefully inspect the plastic film in the greenhouse and find holes, cracks, and repairs immediately. In addition, the plastic film laid on the ground should be firmly bonded with mud. In this way, cold air can be prevented from entering the shed and the temperature of the shed can be increased.
Third, grass cover shed
Since grasshoppers are poor conductors of heat, heat loss in the shed can be reduced and temperature reduction can be avoided. Therefore, straw, corn, wheat straw, and other crop stalks can be used to make haystacks. As long as there is no sun, they cover the sheds. When sunlight is seen, the grass pods are removed in time. In addition, before the cold current approaching, adding grass or corn stalk around the shed at night can increase the temperature of the shed by 2°C to 3°C. When the temperature drops suddenly, it can be covered with a layer of common agricultural film or old film, which can improve the heat insulation of the grasshopper and prevent rain and snow from wetting the grasshopper.
4. Take a shed in the greenhouse
In order to prevent seedlings and weak seedlings in greenhouses from freezing, a plastic shed can be placed on seedlings or weak seedlings before the bad weather comes. This is equivalent to using a double-layer film to protect the temperature in the shed. This method is mainly applicable to flat hoe cultivation.
V. Addition of temporary heat source
In order to relieve cold weather, frost, and continuous cloudy weather in time, in a small greenhouse, when a cold stream or frost comes, a stove can be produced in the greenhouse to utilize the heat emitted by the fire to increase the temperature inside the greenhouse. Play antifreeze effect. It is also possible to temporarily set several heaters with a power of 1,600 to 2,500 watts in the shed. However, it should be noted that bathroom heaters should be used. This is because the humidity in the booth is too large and common heaters are used, which are prone to leakage. At the same time, the heater outlet should not be directly facing the crop, so as to avoid overheating the hot air and injuring crops.
Sixth, improve the insulation of the greenhouse back wall
In order to improve the insulation performance of the back wall of a greenhouse, the following measures may be taken: one is to increase the thickness of the back wall of the greenhouse; the other is to put a layer of bricks on the back wall; and third is to construct a hollow heat-insulating wall where hollow parts are filled with straw or polyphenylene. Foam board; fourth is to build a wall of fire, easy to warm, this method is suitable for cold areas.
Seven, smoke around the shed
Before the advent of the cold current, crop straw, firewood, etc. were ignited around the outside of the greenhouse. The smoke produced was used to drive out the cold, so that the temperature around the greenhouse increased, thus ensuring the temperature in the greenhouse was increased and the purpose of resisting cold current was achieved.
Eight, plastic film coverage
When the vegetables in greenhouses are cultivated in high ridges, they can be covered with mulches on the ridges. This can increase the ground temperature by 2°C to 3°C and facilitate watering. However, the ridge height in dry areas should not exceed 10 cm.
Nine, irrigation before the cold snap
The heat capacity of water is so large that even if the cold currents invade and the temperature suddenly drops, the water in the greenhouse is frozen and frozen, and a lot of heat will be released. Therefore, the temperature in the greenhouse will not drop too much, so the soil and air in the greenhouse can be increased. The temperature ensures normal growth of vegetables in the greenhouse.
Tenth, hanging light curtain
On the back wall of the greenhouse, a plastic film or tin foil coated with a metal layer is suspended. The plastic film coated with a metal layer or tin foil is hung on the back wall of the greenhouse. First, the lighting in the shed is enhanced, and the coloration of the fruit in the shed can be promoted; the second is to reduce the absorption of heat energy by the wall and reduce the heat dissipation of the wall. Can increase the temperature inside the shed.
11. Dig out the cold ditch outside the greenhouse
Dig out the cold ditch with depth of 40-60 centimeters and width of 40-50 centimeters outside the greenhouse first, then fill in insulation materials such as sawdust, weeds, horse dung, straw, etc., fill the back cover and seal the ditch, and have a good thermal insulation effect. .
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