Five requirements for winter spinach fertilization

Proper control of nitrogen fertilizer before overwintering. The standard of fertilizer and water management of overwintering spinach before overwintering is to ensure that spinach grows 4-5 true leaves before overwintering. Because spinach with 4 or 5 true leaves has the strongest cold resistance, it is easy to suffer frost injury if it is too big or too small. Therefore, if the sowing time is appropriate and the fertilizer accumulation is sufficient, the application of nitrogen fertilizer should be properly controlled before overwintering to prevent the seedlings from growing and reducing the accumulation of dry matter and sugar. If the sowing is too late or the soil fertility is insufficient, we can consider topdressing nitrogen fertilizer to promote seedling growth to ensure that spinach overwinters at a suitable seedling age.

Apply enough base fertilizer. Overwintering spinach has a long growth period, in order to prevent de-fertilization, base fertilizer must be fully applied. Generally, organic fertilizer and all phosphorus and potassium fertilizers should be used as base fertilizer, and then the soil is prepared to make the bed.

Strengthen fertilizer and water management after turning green. The key to the fertilizer and water management of spinach after overwintering and turning green is to seize the opportunity of topdressing. Topdressing spinach with irrigation, early topdressing after turning green will reduce soil temperature, affect slow seedling and growth, and delay the growth of spinach after topdressing. Generally speaking, it is suitable for overwintering spinach to be applied twice in mid-March, late March and early April, because the external air temperature and soil temperature are steadily rising at this time.

Topdressing after overwintering must be carried out before bolting and flowering of spinach. Because topdressing at this time can prolong the bolting and flowering time of spinach and improve the yield and quality of spinach.

Use ammonium nitrogen fertilizer cautiously. Spinach is sensitive to ammonium nitrogen fertilizer, and the production season of overwintering spinach is in the transitional period of autumn, winter and spring, when the soil temperature is low and the digestion of soil is very weak, so it is best to use less ammonium nitrogen fertilizer and more nitrate nitrogen fertilizer.