How to monitor the humidity and illuminance in a greenhouse

The development of modern vegetable facilities began in the early 1980s. In order to solve the supply problem of vegetable baskets, the gap between prosperity and prosperity was alleviated, especially the problem of vegetable production and supply in the low-temperature season. From the traditional method of facility cultivation at that time, we vigorously researched and developed modern vegetable facilities cultivation, including plastic greenhouses and greenhouse cultivation. The role is to keep warm, shelter from rain, and shade. In this regard, it is necessary to label the demonstration greenhouse base with “modernization agriculture” and use advanced detection methods to monitor or control the key elements such as humidity and light in the greenhouse. Among them, we mainly use small weather stations to measure various meteorological conditions within a greenhouse.

Humidity monitoring: The air humidity in the greenhouse is usually relatively large, the relative humidity in the day is 70% to 90%, and it often reaches 100% at night and condenses into water droplets. Excessive humidity in the greenhouse not only affects crop growth, but also causes disease. Therefore, the dehumidification work in the greenhouse is very important. We need to measure the humidity in greenhouses whenever and wherever we can, using greenhouse greenhouse observation stations. In the winter, it is mainly combined with ventilation and cooling. When the weather is fine, it is ventilated and discharged. Cover all the ground in the shed to cover all the places where there is no coverage (ditch), and use straw, chaff, and other materials to minimize the evaporation of soil moisture. The soil in the shed was filled with water, and plastic hoses were placed under the plastic film to spray irrigation. Drip irrigation facilities were available. The spraying of insecticides in the shed should be done on a sunny day. Spraying should not be done on rainy days. If spraying is necessary, it is best to use fumigants and dust agents.

Illumination monitoring: Increasing light under appropriate conditions generally enhances crop photosynthesis and increases crop yields, especially for hi-light crops. The light intensity in the plastic greenhouse is lower than the outside world. The main factor affecting the light intensity in the shed is the quality of the plastic shed film, as well as opaque objects (including scaffolds, laminating lines, brackets, etc.) in the shed. With greenhouse microclimate observation stations can also understand how the light in the greenhouse. The transmittance of the new shed film with good quality generally exceeds 85%. With the extension of the covering time, the shed film is aged and dust is accumulated, and the light transmittance is also reduced. If the film is heavily polluted and has poor quality, the light transmittance can be reduced to less than 50% after 2 years, so the general plastic film can only be used for 2 years. Humidity in the shed is relatively large and often forms water droplets on the ordinary shed film. Water droplets on the shed film also reduce the light transmittance of the shed film. Water droplets on the film can reduce the light transmission rate by 10% to 20%. The production is best done without drip film. At the same time, the presence of opaque objects in the shed should be reduced as much as possible. Shelving and laminating lines should not be excessively thick, and bamboo scaffolds supporting the crops should be replaced by plastic ropes (bundling), which not only reduces shading in the shed but also improves high-crop crops. The light receiving angle.