|Min. Order / Reference FOB Price||Customized logo (Min. Order: 2000 Square Meters)||1000-4999 Square Meters CN¥247.00|
|Supply Ability:||No accurate information|
|Payments:||Visa,On line bank payment,Pat later|
|Type:||Single-Span Agricultural Greenhouses, Glass Greenhouse|
|Place of Origin:||Shandong, China|
Agricultural plastic film greenhouse is a simple and practical protected cultivation facility, because it is easy to construct, easy to use, and requires little investment. With the development of the plastic industry, it has been widely adopted by all countries in the world. The use of bamboo, steel, and other materials, covered with plastic film, built an arched shed for growing vegetables, can be early or delayed supply, increase the output per unit area. Conducive to the prevention of natural disasters, especially the northern region can supply fresh vegetables in early spring and late autumn and low season.
With thermal insulation. After the film is covered, the turbidity in the greenhouse will increase with the increase of the outside temperature and decrease with the decrease of the outside temperature. There are also obvious seasonal changes and large temperature differences between day and night. The higher the temperature, the greater the temperature difference. Generally, the daily temperature increase in the greenhouse in the cold season can reach 3-6℃, and the temperature increase ability in cloudy days or nights is only 1-2℃. The temperature difference between the shed and the open ground gradually increased during the spring and the temperature increased up to 6-15℃. When the outside temperature rises, the temperature increase of the shed meat increases relatively, and the highest temperature can reach more than 20 ℃. Therefore, there are high temperatures and freezing hazards in the greenhouse, which need to be adjusted manually. In high-temperature seasons, a high temperature above 50℃ can be generated in the shed. The whole shed is ventilated, and the outside of the shed is covered with grass curtains or set up as a “pergola”, which can be 1-2°C lower than the open-air temperature. In winter, when the weather is sunny, the lowest temperature at night can be 1-3℃ higher than the open field. On cloudy days, several branches are the same as the open field. Therefore, the main production season of the greenhouse is spring, summer, and autumn. The temperature of the shed can be kept at a suitable growth temperature of 15-30°C through heat preservation and ventilation.
1. Illumination Type and structure of plastic film greenhouse
The light-receiving condition in the small arch shed is related to the type of plastic film, old and new, the degree of contamination, the number of water droplets attached, and the type of shed and the direction of extension of the shed.
Light intensity: The light transmission performance is better, and the light transmittance in the general spring shed is not less than 50% of the natural light intensity.
Light distribution: the closer to the shed film in the vertical direction, the stronger the light. Due to the small height and span of the shed, the internal light distribution is relatively uniform.
Air temperature: The temperature changes drastically under the influence of the outside world, and the temperature difference between seasons and day and night is large.
Under normal conditions, the temperature increasing capacity of the small shed in winter and spring is only 3～6℃. In the small shed covered with grass seed, the temperature can be increased by more than 2℃, and the temperature increasing capacity can reach 5～8℃.
In summer, the maximum temperature of the shed can be 15～20℃ higher than the outside world, which is likely to cause high-temperature hazards, and attention should be paid to ventilation and cooling.
Ground temperature: The change of ground temperature is relatively stable, generally 5-6℃ higher than open ground.
3. Quality classification of humidity potatoes
The airtightness of the plastic film is good. After the small arch shed is covered with the film, the water vapor lost by the ground evaporation and crop transpiration is difficult to escape outside the shed, resulting in high humidity in the shed. The relative humidity in general sheds can reach 70%-100%. At the same time, the evaporated water vapor gathers on the shed film and flows along with the shed film to both sides, often causing the ground humidity on both sides to be too high, resulting in uneven distribution of the ground humidity.
The daily change of air humidity in the small arch shed is relatively large, and the relative humidity is generally 40%-60% during daytime ventilation and more than 90% at night.