The shading net (that is, the shading net) is the latest type of special covering material for agriculture, fishing and animal husbandry. Corrosion resistance, radiation resistance, light and so on. Mainly used for heatstroke prevention and cooling, vegetables, incense, flowers, edible fungi, seedlings, medicinal materials, ginseng, Ganoderma lucidum. After covering in winter and spring, there is a certain heat preservation and humidification effect. Generally, the leafy vegetables planted in winter and spring are covered with the sunshade net directly on the surface of the leafy vegetables (covered by floating surface) to prevent low temperature damage. Because of its light weight, it is only about 45 grams per square meter, which is not suitable for tall leafy vegetables that have grown. It will not overwhelm, bend, or reduce the commerciality. And because it has a certain air permeability, the surface of the leaves is still dry after covering, which reduces the occurrence of diseases. It also has a certain degree of light transmittance, and it will not "cover yellow and rot" after covering. The role of the shade net: One is to block strong light and reduce high temperature. Generally, the shading rate can reach 35%-75%, accompanied by a significant cooling effect; The second is to prevent rainstorms and hail disasters; The third is to reduce evaporation, protect moisture and prevent drought; Fourth, heat preservation, cold protection, and frost protection. According to the test, the nighttime covering in winter and spring can increase the temperature by 1-2.8℃ compared with the open field;