棉花采用塑料薄膜覆盖育苗,在管理上花工费时,且技术要求高,难度大,操作中稍有不慎便会造成高温烧苗或低温伤苗。为了既能保留薄膜育苗的优点,又能克服其弊端,使育苗方法简便易行,安全可靠,并能提高棉苗素质和适应家庭联产承包责任制的形式,我们应用苗床内外温差形成空气对流、自动平衡的原理,设计了一种半封闭的 Cotton film covered with plastic nursery, management time-consuming, and high technical requirements, the difficulty of large, inadvertently operation will result in high temperature burning seedlings or cold wounds. In order to not only retain the advantages of film nursery, but also overcome its shortcomings, make the nursery method easy, safe and reliable, and improve the quality of cotton seedlings and adapt to the household contract responsibility system. We use the temperature difference between inside and outside the seedbed to form air convection , The principle of automatic balancing, the design of a semi-closed