The cost of greenhouses is very high, so its seedling raising efficiency is much better than other types of greenhouses. In order to make everyone more comfortable to apply it, we should master its seedling raising methods. In the greenhouse in winter and spring, the calendar seedling age is 35 to 55 days, the temperature is low, the seedling period is long, and vice versa, the physiological seedling age is 3 to 4 leaves, and the sowing period is generally controlled by 40 to 45 days.
1. Seedling raising method: use nutrient bowl greenhouse to raise seedlings. Since this cucumber seedling is raised in the season with the worst sunlight and lowest temperature of the year, it is necessary to do a good job of preventing cold and heat preservation of the seedbed. First, try to choose to build the bed in the middle of the greenhouse with the best temperature and light; second, install heating facilities, such as heating materials, geothermal wires, and add light bulbs in the shed; third, add small arch sheds and arch sheds on the ground Don't be too small, the height should be up to 1 meter, and prepare a cover to protect it at night and when the temperature is low.
2. Bed soil preparation: Take 7 parts of fertile soil that has not grown vegetables, 3 parts of decomposed high-quality circle fertilizer, 1 cubic meter of bed soil plus 10-15 kg of decomposed chicken manure, 15 kg of plant ash, 1 kg of superphosphate, and 0.5 ammonium sulfate. Kg, or 0.5 kg of diammonium phosphate, the various materials are sieved first and then compounded, and mixed thoroughly for later use.
There are many types of greenhouses. Due to the difference in the cost of greenhouses, the humidity control methods in the greenhouses are different, but different control methods have the following characteristics:
1. Humidity control system design: The humidity control system first detects the humidity status in the greenhouse by a humidity sensor. The method to reduce indoor humidity is: the first step is to open the skylight for natural ventilation; the second step is to use an axial fan for forced ventilation. When the indoor humidity is too low in summer, the humidity is increased by the humidifying device of the wet curtain fan.
2. Humidification effect: According to the temperature and humidity records for two consecutive years in August, except for rainy days, the average indoor humidity in the afternoon is generally about 60%. For crop growth, the humidity is too low, transpiration is strong, and photosynthesis occurs. Lunch break phenomenon. When using the wet curtain cooling system, the air humidity will continue to increase, generally to 78%-85%, this humidity is very suitable for crop growth. Since the temperature of the wet curtain on a sunny day cannot be lowered to the level of the wet bulb temperature, the humidity will not be too high. In the rainy season or cloudy and rainy days, the atmosphere itself is very humid. After using the wet curtain cooling system, although the humidity cannot be reduced, it will not increase the humidity significantly. Compared with atomization cooling, spray cooling and other methods, wet curtain cooling has a smaller increase in atmospheric humidity.
3. Dehumidification effect: In the rainy season, high humidity in the greenhouse is the main contradiction of the greenhouse environment in summer. After opening the skylight for natural ventilation, due to the limited opening area of the skylight, the indoor humidity is generally higher than that of the outdoor; after the use of axial fan forced ventilation, the humidity can be reduced to the same level as the outdoor, and the airflow caused by forced ventilation can be Reduce the probability of disease occurrence.
Many people use greenhouses to grow crops. Different greenhouses have different greenhouse costs. In order to reduce the cost of greenhouses, we must choose suitable greenhouses according to the conditions of greenhouse selection. Let’s understand the greenhouses below. The light conditions of the greenhouse.
The light conditions of the greenhouse mainly include four aspects: light intensity, light hours, light distribution and light quality. These four factors interact with each other and form complex light conditions.
The lighting conditions of greenhouses are mainly affected by latitude, seasons, weather conditions, covering materials and structural properties. In the northern region, the winter greenhouse is in the season of weak light intensity and short sunshine time. In addition, the reflection, absorption and refraction of the transparent covering material causes the loss of light intensity. The heat preservation cover reduces the light hours and the light conditions are very poor. The higher the latitude, the more serious this situation is.
In the spring, the height of the sun rises, the intensity of natural light increases, and the light intensity of the greenhouse gradually improves. Most of the plastic greenhouse production in the northern region is after March, and the sunlight conditions such as sunshine intensity and sunshine hours are better than winter greenhouses, which generally can meet the needs of fruit and vegetable growth.
Greenhouses generally extend east-west, with the light-transmitting side facing south. Due to the influence of the back slope shading surface, the light intensity in the north is weaker than that in the south. Especially after the Ching Ming Festival, the rear of the greenhouse can hardly be used for production. Plastic greenhouses receive even more light than greenhouses, especially those extending north and south. There is a weak light zone in the north of the plastic greenhouse extending from east to west, and the light intensity is lower than that in the south.
