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一、用聚氯乙烯无滴、长寿、多功能膜代替聚乙烯普通膜。据试验,同样厚度。前者较后者平均提高棚温5℃,使用时间延长1/3～1/2,前者透光率保持在89％以上。 二、采用双层薄膜保温。即在大棚内加盖地膜或设置小拱棚,加盖地膜能使地温增加2～3℃,设置小拱棚,可使小拱棚内的温度保持在10℃以上,确保蔬菜在早春正常生长。 三、用塑料胶带补膜代替线缝、热压补膜。采用线缝补膜,不仅补不严,而且易撕裂,透风漏气,影
First, with PVC no drip, longevity, multi-functional film instead of polyethylene ordinary film. According to the test, the same thickness. The former than the latter to improve the shed temperature 5 ℃, the use of time to extend 1/3 ~ 1/2, the former transmittance remained above 89%. Second, the use of double-film insulation. That is, in the greenhouse covered with plastic film or set a small shed, covered with plastic film can increase the ground temperature 2 ~ 3 ℃, set a small arch, the arch can be maintained within the temperature above 10 ℃, to ensure the normal growth of vegetables in early spring. Third, replace the seams with plastic tape film, hot film. The use of seams make up film, not only make up lax, but also easy to tear, air leakage, shadow