Shade net shade net, also known as shading, in the last 10 years to promote a new type of agriculture, fisheries, animal husbandry, wind, mulch and other special protective covering materials. After the summer, play a cover block light, rain, moisture, cooling effect. After the winter and spring, there is a certain degree of insulation covering humidification effect. The shade net directly on the surface of leafy cover of (superficial coverage), to prevent hypothermia harm, because it is lightweight, only about 45 grams of high trees have grown leafy vegetables will not overwhelm, bending per square meter, reduced marketability. Because it has a certain breathability, after covering the surface of the leaves are still dry, reducing the occurrence of disease. It also has a certain degree of transparency, after covering it will not "cover yellow cover rotten." 1997 Henan Agricultural University in Long Hall Linying vegetables have basically grown into a park for winter greenhouses celery, superficial coverage in the shed were carried out cold protection, shade net and found superficial coverage who were in the external situation -6 ℃ celery leaf did not find a lot of ice; and single shed controls, especially in the upper leaves have been frozen hard, the determination of coverage were higher than the control temperature of 1.5 ℃. Mainly used shade net shade net is mainly used in the summer, especially in the South to promote a large area. Some say: the northern winter is a white (mulch), Southern summer is a black (cover shade net). Summer in the South use shade net cultivation of vegetables has become a disaster prevention and technical measures to protect a major promotion. Application is also limited to the northern summer vegetable seedling. Summer (June-August) covering shade net primary role is to irradiate the anti-sun, the anti-storm impact hazard, high temperature spread of pests and diseases, especially to prevent pest migration play a good role. Play after a summer cover block light, rain, moisture, cooling effect; after winter and spring there is some insulation covering humidification effect. Moisturizing principle: [1] after obscure shade net, because the cooling effect of wind, down obscure area outside air and the speed of communication, significant progress on the progress of the air relative humidity, at noon, humidity increases the maximum value, the general progress of 13-17% high humidity, soil evaporation decreased, increasing soil moisture. Shade net is the use of polyethylene (HDPE), high density polyethylene, PE, PB, PVC, recycled materials, new materials, polyethylene C class for raw materials, UV stabilizers and oxidation treatment, with a strong tensile, aging resistance, corrosion resistance, radiation, light and other characteristics. Mainly used for vegetables, mushrooms, flowers, edible mushrooms, seedlings, herbs, ginseng, fungus and other crops cultivation and protection of aquatic poultry, etc., to improve the yield and other significant effects. Classification round wire shade net shade net: Because shade net is woven from the warp and weft cross, mainly woven warp knitting machine, so if the warp and weft are made of round wire braid that round wire shade net. Figure: Biansi shade nets: the warp and weft are flat yarn woven shade net shade net is flat yarn, this network is generally low weight, high shade, mainly for agriculture, sun shade garden. Figure: Round flat silk shade net: warp is flat, round silk weft or warp a round wire, flat wire weft is the case, the sun is round flat wire mesh woven shade net. Figure: How to cover the best one, when covering shade net, should the weather changes, celery grown in different periods, to strengthen the management of shade net. Celery day before emergence should cover net, after emergence expose network should see the light sooner or later ends at noon when the sun is strong cover. Cloudy encounter can not cover all day, but the former must be timely rainstorm cover net. Second, use the width of the shade net can be cut and spliced. Cutting method is to use an electric wire heat cut off due to high fever shade nets can melt to form a channel, not loose. Splicing method is to use the sewing machine or hand-sewn with nylon thread, do not use wire or aluminum wire bundles ligation to avoid mechanical breakage, which will affect the life of shade nets. Third, the superficial coverage will cover shade net directly on the ground or plants, generally at planting, after planting. Fourth, the small shed covered with shade net will cover small shed on the film's arch bracket, suitable for summer and autumn shading, cooling, ventilation or early spring frost at night, can also be used in the rainy winter night, rain or insulation. Fifth, do a good job of covering the flat roof surface barricaded shed 0.5 to 1.8 meters tall flat or tilting bracket, the shade net cover on the stand for shade and rain. Six greenhouses covering greenhouses covering network coverage is divided into single, retinal binding coverage, Pengwai around coverage and canopy coverage. Single network and omentum with covering both sides of the shed about one meter off the ground is not covered by the general vacant. Pengwai four weeks covering, insulation and more for early spring night. Canopy cover, generally 1 to 1.5 meters off the ground without cover. Seven, the main purpose of the various growth stages after sowing coverage is coverage 1. conserve soil moisture, prevent soil compaction after rain. Prevent insects, bird damage. Method is generally directly cover on the ground, but after emergence to timely expose network, so as not to impede the growth of seedlings. 2. The short-covering after planting, and one is to be covered for the summer after planting cabbage, cauliflower, cabbage, celery, lettuce, etc., has been covered so far to survive, day night cap to expose directly covering the crop; the other species in the evening for early spring planting of eggplant fruit, melons beans covered to prevent frost.