伊人久久综合狼伊人久久_久久久久久精品免费免费麻辣_久久久久久精品免费免费WE_中文字幕无线码一区2020青青

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.



少妇极品熟妇人妻无码| 人妻无码久久一区二区三区免费| 国产精品18久久久久久vr| 嫩b人妻精品一区二区三区| 无码人妻啪啪一区二区| 欧美xxxxx在线观看| 久久久一本精品99久久精品88 | 国产免国产免‘费| 丰满迷人的少妇特级毛片| 丰满少妇a级毛片野外| 色噜噜狠狠一区二区三区| 久久久久国色av∨免费看| 美女网站免费福利视频| 国产日韩欧美| 国产麻豆天美果冻无码视频| 少妇无码av无码专线区大牛影院| 久久精品国产精品亚洲毛片| 狠狠色综合网站久久久久久久 | 亚洲av中文无码乱人伦在线观看| 夜精品a片一区二区三区无码白浆| 亚洲成av人片在线观看麦芽| 色狠狠色噜噜av天堂一区| 欧洲精品免费一区二区三区| 日韩少妇内射免费播放| 国产精品无码一区二区三区| 初尝黑人巨砲波多野结衣| 小鲜肉自慰网站| 亚洲成a∨人片在线观看无码| 在线精品国产成人综合| 丰满爆乳无码一区二区三区| 日产精品久久久一区二区| 久久精品国产99久久久古代| 日韩视频 中文字幕 视频一区| 人人摸人人操| 欧美成人一区二区三区| 性高湖久久久久久久久aaaaa| 熟妇女人妻丰满少妇中文字幕| 精品国产拍国产天天人| 久久久精品人妻一区亚美研究所| 99久热在线精品996热是什么| 欧美a∨在线观看|