Although the reflective curtain is good to use properly
Many vegetable farmers have this feeling, saying that the reflective screen is good, but they have no effect when they use it, and they do n’t feel much increase in production. What is the reason? When the reporter went to the countryside, he saw a lot of hanging reflective screens, thinking that the problem lies with the vegetable farmers themselves, and did not make good use of the advantages of the reflective screens for reasonable use.
In this regard, teacher Zhu Zhenhua reminded vegetable farmers to use the reflective screen to pay attention to the following points:
First of all, in the early stage of planting, pay attention to watering near the reflective screen, and the water should be sufficient to prevent the burning of seedlings due to strong light and high temperature. The valid time is generally from November to April of the following year. For a solar greenhouse without a backslope, the reflective curtain needs to be hung on the north wall, and the front side of the aluminized film should be facing the sun, otherwise the film surface is too close to the wall, and the aluminum film is liable to fall off due to humidity. After use every year, it is best to dry it and store it in a ventilated and dry place for reuse.
Secondly, the reflective screen must be applied in a solar greenhouse that reaches the photosynthetic temperature. If the greenhouse is not well insulated, it is effective to increase the temperature and ground temperature in the greenhouse by a reflective screen during the day, but it will inevitably be damaged by low temperature at night. Because the main role of the reflective curtain is to increase the light intensity and daytime temperature at the rear of the greenhouse, and expand the temperature difference between day and night at the rear, so as to tap the potential of increasing crop yield at the rear.
In addition, the angle and height of the reflective screen need to be adjusted appropriately with the season and crop growth. In winter, the sun height angle is small, and the height of the reflective curtain is generally low, especially for dwarf crops. The lower side of the reflective curtain should be near the ground or close to the top of the plant, and the vertical suspension or the upper side should be slightly southward. When fruits such as cucumber and tomato and solanum-like tall vegetables are bearing fruit, the height of the plant is high, and the requirements for leaves increase. Especially when the morning and evening light is strong, the height of the reflective curtain should be appropriately raised to the bottom edge. It is advisable to raise the position near the top of the tall stalk crop, and the angle is mainly inclined to the south slightly. In spring, the height of the sun will increase by itself, and the top of the reflective screen will be tilted to the north and adjusted to maintain a 75-85 degree angle between the reflective screen and the ground plane, so that within two hours after sunrise and within two hours before sunset The reflected light is basically level with the ground as well. After entering April, as the temperature rises, the light is sufficient, and the weak light and ground temperature factors that restrict the growth and development of vegetables no longer exist. At this time, the reflective curtain has completed its role and should be removed in time.
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The instrument workbench adopts high-precision horizontal air floating track and rolling vertical track, with high movement accuracy, good stability, and long service life; High measurement efficiency, convenient card installation, simple operation, suitable for use in workshop inspection stations or measurement rooms. This instrument can further develop software according to the needs of users, meet their measurement shape requirements more widely, and is equipped with various equipment components for users to choose and use according to their own requirements.
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