99久久久国产精品免费蜜臀,九色综合九色综合色鬼,少妇三级全黄,夜夜揉揉日日人人

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.



亚洲人成人无码www| 久久国产劲爆∧v内射| 青青草原综合久久大伊人精品| 亚洲av永久无码精品一区二区国产 | 国产精品 无码专区| 中文字幕亚洲综合久久| 久久久受www免费人成| 免费特级毛片| 无遮挡啪啪摇乳动态图gif| 97在线观看| 少妇精品久久久一区二区三区| 国产精自产拍久久久久久蜜| 亚洲综合色无码| 国产伦精品一区二区三区免费| 免费人成视频在线播放| 日韩丰满少妇无码内射| 国产美女自慰在线观看| 日本最大色倩网站www| 国产女人精品视频国产灰线| 三年片在线观看免费观看大全中国| 99精品久久久久久久婷婷| 色综合久久网| 欧美尺寸又黑又粗又长| 久久久噜噜噜久久中文字幕色伊伊| 黑人巨大精品欧美一区二区免费| 国产三级在线观看免费| 亚洲精品亚洲人成人网| 中文在线а天堂中文在线新版| 午夜福利麻豆国产精品| 精品久久久久久无码中文字幕| 在厨房被c到高潮a毛片奶水| 亚洲午夜精品一区二区 | 无码人妻一区二区三区精品视频| 欧美亚洲色综久久精品国产| 日本丰满少妇xxxx| 波多野结衣久久精品99e| 99精品国产综合久久久久五月天| 日韩一区国产二区欧美三区 | 俺去啦最新官网| 国产成人精品久久| 久久精品动漫一区二区三区|