把蔬菜从陆地上栽培移进温室和塑料大棚内生产，是人类进行蔬菜栽培生产的一大进步。可是在几十年的生产实践中，人们只是从事简单的单一品种一季栽培生产，后来发明了早春提前和晚秋延后蔬菜生产技术，把保护地的蔬菜栽培变为早春提前和晚秋延后生产，产量得到了提高，经济效? Vegetable cultivation from the land into the greenhouse and plastic greenhouse production, human cultivation of vegetables is a big step forward. However, in decades of production practice, people only engaged in a simple single-species cultivation of the first season, and later invented the early spring and late autumn delayed vegetable production technology, the protective vegetable cultivation into early spring and late autumn delayed production, Yield has been increased, economic efficiency?