大白菜是北方的主要蔬菜之一,但因受自然条件的影响,产量极不稳定。大白菜的播种期到苗期,常常遇到气候障碍,如雨水多,不能进行作业;苗期干旱,影响全苗;中午地表高温,烤伤烤死幼苗,造成缺苗和幼苗不整齐。这些不利因素极易导致减产,形成大白菜的大小年。我区从1989年采用营养钵育苗和高畦覆膜栽培法,在5亩秋大 Chinese cabbage is one of the main vegetables in the north, but due to natural conditions, the output is extremely unstable. Chinese cabbage sowing period to seedling stage, often encounter climatic obstacles, such as rain, can not operate; seedling drought, affecting the whole plant; noon surface temperature, roasted grilled dead seedlings, resulting in lack of seedlings and seedlings. These adverse factors can easily lead to cut, the size of the formation of Chinese cabbage. My district from 1989 using nutrition bowl nursery and high tofu film cultivation method, in 5 acres QiuDa