2. The layout is reasonable. In order to facilitate centralized management, custody, pre-natal, mid-natal and post-natal services, and facilitate centralized marketing and dissemination of technology, large-scale production should be carried out on concentrated plots in villages. In order to prevent the shed from being closed, the shed spacing should be not less than 8m, preferably 16m, so that the shed can be comprehensively utilized, some sun beds and small arches can be built appropriately, and an excellent microclimate environment can be formed.
3. The direction of the shed. It is best to face due south and face east and west. Because the main production period of greenhouse in winter is 65438+February-March, during this period, due to the timely morning light in the south, there is the most sunshine all day, but things are not good. Under special circumstances, if there are terrain restrictions, the east or west angle cannot exceed 5 degrees.
4. Construction time. The autumn and winter crops in the greenhouse can be planted as early as September, so they will be built at the end of September. If winter and spring crops are planted late, the wall should be built in the middle of June 5438+ 10, so that the wall can be dried thoroughly and there is enough time for soil preparation, fertilization, soil maturation and "baking" before planting.
5. The size of the shed. The shed is 50 meters long, and the overall space below 50 meters is small, which is not conducive to thermal insulation; More than 50 meters, because the shed is too long, the transportation operation is inconvenient, and it takes too long to open the straw curtain, which shortens the time for crops to see the light.
The width of the shed should be 6-7 meters. If it is more than 7 meters, it is necessary to increase the height of the back wall and the back column to keep the best incident angle of sunlight in winter, which is uneconomical, labor-intensive and costly. If it is less than 6 meters, the planting area is small and it is not practical.
The height of the shed is the height of the ridge, 3 meters. If it is 10 cm high or low, it will destroy the overall design and waste manpower and material resources. After the height is determined, the distance from the back column to the back wall should be1.4—1.5m. ..
Extended data
Greenhouse is mainly composed of enclosure wall, back roof and front roof, which is the "three elements" of solar greenhouse. The front roof is the whole lighting surface of the greenhouse, which is only covered with plastic film during the day. When the outdoor light is weakened, plastic film should be covered in time to strengthen the heat preservation of greenhouse.
Due to the development of plastic industry and the breakage of glass, most rural greenhouses use plastic films as roofing materials. In particular, plastic greenhouses in northern China, which are dominated by earth greenhouses, have obvious characteristics of high efficiency, energy saving and low cost, and are welcomed by vegetable farmers and consumers. It is one of the effective measures to develop high-yield, high-quality and high-efficiency agriculture, and will develop faster.
Practice has proved that satisfactory results can be achieved when the lowest outdoor temperature is not lower than -25℃ and the indoor temperature is kept above 5℃ by using the special structural properties of plastic greenhouses.
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