我国栽培水稻地区,过去大都采用水田育秧,即自播种至栽秧,秧田经常蓄水。在春季寒冷的情况下,加以秧田管理不适当,排灌水不适宜,或灌水过深过浅,影响幼苗的正常呼吸作用和光合作用,继以病菌侵袭,常有可能遭致严重的烂秧,造成缺秧,影响收获;或者春季乾旱,缺水育秧,延迟播種甚至无法下种;在稻麦两熟地区,由于小麦生长期较长,影 Rice cultivation areas in our country, the past mostly used paddy field nursery, that is, from sowing to planting, seedling often water. In the case of cold in the spring, unsuitable management of seedling, irrigation and drainage of water inappropriate, or too shallow irrigation, affecting the normal respiration of young seedlings and photosynthesis, followed by pathogen invasion, often may be caused by severe rotten seedlings, Resulting in lack of seedlings, affecting the harvest; or spring drought, lack of water seedlings, delayed seeding or even under the species; in the wheat and wheat two ripe areas, due to the longer wheat growth period, the shadow