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>

          Black sun screen dust screen

          Canopy products > Shading net > Black sun screen dust screen

          Black 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.



          日韩人妻中出香蕉久久精品| 欧美性欧美巨大黑白大战| 日韩精品一二三区在线播放| 一本大道久久精品一本大道久久| 岛国中文字幕一区二区| 久久精品人妻少妇一区| 亚洲女人天堂av在线| 国产欧美一区二区精品性| 国产美女一区免费观看| 国产av一区二区精品| 台湾佬中文娱乐网综合网| 亚洲一区二区三区四区中文| 国产人妻宾馆与情人在线| 日本一区二区三区内射| 丁香婷婷激情综合俺也去 | av熟女乱入一区二区| 色综合天天久久天天久久| 人妻的屁股一区二区三区| 日本一区二区三区专区| 少妇熟女av一区二区三区| 亚洲性码不卡视频在线| 亚洲av综合av综合| 男人的天堂在线观看av| 日韩在线一区二区三区免费视频 | 最新永久无码AV网址亚洲| 丰满少妇女人A毛片视频| 狠狠躁夜夜躁人人爽天天5| 国产国产精品人在线观看| 99精品众筹模特自拍视频| 亚洲中文字幕国产精品| 亚洲男人的天堂在线播放| 午夜福利精品一区二区| 中文乱码字幕视频在线观看| 精品日本韩国一区二区三区| av一区二区在线观看| 国产成人av大全在线观看| 成人做受视频试看120秒| 精品免费国产一区二区| 国产日本韩国欧美三级| av不卡一区不卡二区国产| 亚洲av区一区二区三|