1、控氮法:苗期适当减少氮肥用量,切不可偏施 氮肥,以免植株抗寒力差。追肥要早,以促使菜苗老 健。低温之前,不能施用速效氮肥,宜追施一次磷钾 肥,以增强抗寒力。 2、施有机肥法:用猪牛粪或土杂肥等暖性农家 肥,圈培在菜棵根颈处,可提高根部土温2-3℃。施肥 宜趁晴天进行,每亩1000-1500公斤。 1, nitrogen control method: the appropriate amount of nitrogen to reduce seedling stage, must not partial nitrogen fertilizer, so as to avoid poor cold hardiness. Top dressing to be early, in order to promote vegetable seedling health. Cryogenic, can not be applied quick-acting nitrogen fertilizer, should be topdressing a phosphate fertilizer to enhance the cold resistance. 2, the organic fertilizer method: with pig manure or Tuza Fei and other warm manure, ring culture in the root of the neck, can increase the root soil temperature 2-3 ℃. Fertilizers should take advantage of sunny days, 1000-1500 kg per mu.