Sufficient light, carbon dioxide, water, and temperature are necessary conditions for plant growth. How can we ensure the balance of these factors in a special greenhouse environment?
Ensure sufficient light
Adequate lighting is a guarantee for the high yield of crops in greenhouses. In winter-warm plastic greenhouses without artificial heating, lack of light is a major factor limiting production. The data shows that the internal light of newly-built greenhouses (new booths) is reduced by 10% to 15% compared with natural light. When there is dust in the shed film or condensation in the film, the illumination in the shed can be reduced by more than 50%. The recommended method to solve the problem is to install 1000 watt fluorescent lamps in the shed to make up the light. Fluorescent lamps are suspended in the middle of the shed. Whether or not to hang two or more rows depends on the width of the shed. The light is more than 35 centimeters from the top of the crop, and is installed every 3-5 meters. It is usually lighted once in the morning and in the afternoon, and the lighting time depends on the sunlight conditions to maximize the demand for crop photosynthesis. . At the same time, there are fewer pests and diseases in greenhouses with adequate sunlight.
Appropriately increase carbon dioxide concentration
Under the premise of solving the problem of good light, the concentration of carbon dioxide in the shed has become one of the factors affecting crop yields in the greenhouse. Under normal circumstances, due to crop respiration and soil release before sunrise, the carbon dioxide concentration inside the greenhouse is 2-3 times higher than that outside the greenhouse (300-350 ppm). After 8 o'clock, with the increase of photosynthesis, it can be reduced to less than 100 ppm. Therefore, it is recommended that after 8 o'clock, it should be reasonable. One to supplement carbon dioxide, and second to discharge harmful gases (such as ammonia, nitrogen dioxide, ethylene, etc.). Under the condition of weak light and low temperature in winter and spring, artificial carbon dioxide application has obvious effect of increasing production.
Add warming facilities
In winter or early spring, the outside temperature fluctuates widely. In case of heavy snow or cold current, the shed crops are often exposed to low temperature hazards and poor growth. It is suggested that in order to ensure the basic temperature in the shed (the crop is not affected by chilling) during special cold weather, warming equipment should be turned on to prevent production loss. The main methods are: heating lines to increase ground temperature, electric heating or furnace warming. Another simple and easy method is to place water bags (plastic bags filled with water) in the greenhouse. Using the characteristics of large specific heat of water, during the day, the water bags absorb solar energy in large quantities, convert it into heat energy and store it, and release it gradually at night. Come out and increase the temperature of the greenhouse.
Reasonably regulate the humidity in the booth
The humidity in the shed not only affects crop photosynthesis and mineral nutrients, but also directly affects the occurrence of pests and diseases. The law of humidity change is that the greenhouse is closed, the air in the shed is exchanged with the outside air, the soil evaporation and the transpiration of the leaf surface are difficult to distribute, so the humidity in the shed is large. If no dehumidification measures are taken, the relative humidity of the air in the shed is 70%-80% even during daytime ventilation, 90% or more after rainy days or irrigation, and 100% at night (because the air relative humidity in the shed will follow At night, when the temperature of the shed drops and the cover grass rises, the wet air in the shed will condense into a water film or the water droplets will adhere to the inner surface of the plastic film or the leaf stalk of the crop, which is extremely beneficial to the spore germination and infection.
The effective methods of dehumidification include: (1) Ventilation and ventilation when the temperature is high and humidity; (2) Warming in the shed when the temperature is low and humidity is high; (3) The drip irrigation technology is used to save water and fertilizer; (4) Adoption Plastic film covering cultivation techniques, maintaining ground temperature, reducing soil moisture evaporation, reducing the number of watering, and can significantly reduce the air humidity of about 20%; (5) can be placed in the shed strong absorbent material.
Cpe Disposable Gloves,Plastic Protective Gloves,Pro Safe Disposable Gloves,Hospital Disposable Gloves
Shandong Haoyue Medical Technology Co., Ltd , https://www.haoyueyiliao.com