一区白丝二区精选精品,欧美成人一区二区免费,91亚洲国产成人久久,亚洲精品乱码久久久蜜臀,日韩av大片免费在线观看,国产又黑又粗又黄又爽,日韩中文字幕美艳人妻,欧美丰满大屁股在线喷水,日韩欧美国产午夜视频,一级黄片国产精品久久

    <rt id="4xhpc"><small id="4xhpc"></small></rt>
        <li id="4xhpc"></li>
        1. <label id="4xhpc"></label>
          <li id="4xhpc"></li>

          Green sun screen dust screen

          Canopy products > Shading net > Green sun screen dust screen

          Green sun screen dust screen

          Model of sunscreen: 2.5, 3, 3.5, 4, 6, 8, 12

          Model of sunscreen: 2.5, 3, 3.5, 4, 6, 8, 12

          Shade color: black, green

          Sunshade net, also known as sunshade net, is a new type of special protective covering material for agriculture, fishery, animal husbandry, windbreak, soil cover and so on, which has been popularized in recent 10 years. After covering in summer, it plays a role of keeping out light, rain, moisture and temperature. After covering in winter and spring, it can keep warm and increase humidity.

          Generally, the leaf vegetables planted in winter and spring cover the surface of leaf vegetables directly with sunshade net (floating cover) to prevent low temperature damage. Because of its light weight, it is only about 45 grams per square meter, and it will not overwhelm, bend or reduce the commerciality of the grown high leaf vegetables. Because of its air permeability, the leaf surface is still dry after covering, which reduces the occurrence of disease. It also has a certain transparency, after covering, it will not "cover yellow, cover rotten". In 1997, Henan Agricultural University in Longtang vegetable Park, Linying County, protected the winter celery in the shed. The results showed that under the condition of - 6 ℃, there was no ice in the leaves of celery; However, the temperature of the control group, especially the upper and middle leaves, was 1.5 ℃ higher than that of the control group.

                 Sunscreen is mainly used in summer, especially in the south. Some people describe it as: the winter in the north is white (covered with film), and the summer in the south is black (covered with sunscreen). In summer, using sunshade net to cultivate vegetables in South China has become a main technical measure for disaster prevention and protection. The application in the north is only limited to the cultivation of vegetable seedlings in summer. In summer (June August), the main function of covering sunshade is to prevent the exposure of hot sun, the impact of rainstorm, the harm of high temperature, the spread of pests, especially to prevent the migration of pests.

                 After covering in summer, it plays a role in keeping out light, rain, moisture and cooling; after covering in winter and spring, it also has a certain role in heat preservation and humidification.

                 Moistening principle: after the sunshade is covered, because of the cooling and windproof effect, the communication speed between the air in the covered area and the outside world is reduced, the relative humidity of the air is significantly further increased. At noon, the humidity increase value is the largest, generally reaching 13-17%. The humidity is high, the soil evaporation is reduced, and the soil humidity is increased.

                 The sunshade is made of polyethylene (HDPE), high-density polyethylene, PE, Pb, PVC, recycled material, brand-new material, polyethylene propylene and other raw materials. After UV stabilizer and anti-oxidation treatment, it has the characteristics of strong tensile strength, aging resistance, corrosion resistance, radiation resistance and portability. It is mainly used in the protective cultivation of vegetables, Xianggu, flowers, edible fungi, seedlings, medicinal materials, ginseng, Ganoderma lucidum and other crops, as well as the aquaculture and poultry industry, etc., which has obvious effect on improving the yield.



          久久精品国产免费av| 青草免费在线观看国产| 日韩高清中文字幕在线| 一本大道视频精品人妻| 亚洲熟妇精一区二区三区| 伊人精品成人久久综合全集观看| 亚洲国产精品久久66| 亚洲国产日韩精品四区| 欧美婷婷久久五月精品三区| 欧美久久这里只有精品| 午夜精品福利一区三区| 国产精品人成在线播放新网站| 亚洲精品国产精品乱码不99| 国产欧美精品区一区二区三区 | 色窝窝无码精品AV| av日韩精品在线播放| 中文字幕av一区二区| 国产成人欧美视频在线观看| 中文字幕巨大的乳专区二区| 亚洲av熟妇一区二区三区| 亚洲欧美一区二区综合精品| 国产成人自拍视频在线| 亚洲美女在线免费激情| 久久国产丝袜三级视频| 日韩成人在线视频播放| 久久99国产精品尤物| 国产成人av专区一区| 天堂av资源在线免费| 亚洲s码在线一区二区| 北岛玲精品一区二区三区| 国产精品一区二区三密桃| 国产精品视频一区二区三区免费| 亚洲毛片av在线观看| 亚洲欧美日韩人妻在线| 久久久9色精品国产一区二区三区| 欧美日韩一区二区三区性感| 亚洲av综合日韩精品久久久| 中文日本精品视频在线| 国产精品中文一区二区三区| 日韩成人在线精品视频| 成年深夜福利在线观看|