油菜越冬后,进入春发时,科学施肥很关键。要掌握“早、重、喷、补、巧”五字诀。 一、早施返青肥 返青肥也称春肥、开盘肥。早施的目的是及时弥补冬季生长之不足,促使分枝多、根系旺、根颈粗、菜苗壮。一般宜在“立春”前后施,以碳酸氢铵等速效性氮肥为主,每亩可施碳酸氢铵15～20公斤,或硫酸铵12～15公斤。对前期未施磷、钾肥或用量不足,出现缺磷缺钾症状时,每亩可补施过磷酸钙10～15公斤,氯化钾5～8公斤;对冬季生长过旺的类型,返青肥可以不施或少施,适当延迟施肥时间;对春后生长瘦弱的田块,应增加氮肥用 After rape overwinter, into the spring, scientific fertilization is the key. To master the “early, heavy, spray, make up, clever” five-word tactic. First, as early as the return of green manure also known as spring green fertilizer, open the fat. As early as the purpose is to make up for the lack of winter growth, to promote more branches, root Wang, root neck coarse, vegetable seedlings Zhuang. Generally should be in the “before spring” facilities to ammonium bicarbonate and other quick-acting nitrogen-based, ammonium bicarbonate per acre can apply 15 to 20 kg, or ammonium sulfate 12 to 15 kg. On the early no phosphorus, potassium or lack of dosage, the emergence of phosphorus deficiency and potassium symptoms, per acre can be supplemented with superphosphate 10 to 15 kg, potassium chloride 5 to 8 kg; winter over-growth type, Can be applied or less, the appropriate delay fertilization time; thin spring field growth, should increase the use of nitrogen