Apple's fertilizer requirement: According to the survey of apple orchards with an output of more than 5,000 kilograms per mu, the ratio of nitrogen, phosphorus and potassium is 2:1:2. Generally, for every 1000 kilograms of fruit, 4 to 7 kilograms of nitrogen are needed, and phosphorus is 2 to 3.5 kilograms. Potassium 4~ 7 kilograms; the main stage is nitrogen, and the middle and late stage is mainly potassium. The absorption of phosphorus is relatively stable throughout the year.

The main points of apple fertilization are:

The most suitable period for base fertilizer is autumn, that is, after harvesting of mid-maturing varieties, before harvesting of late-maturing varieties. Followed by leaves until the freezing, and before the spring thawed to the time of germination. Generally, 3500~4000kg of fully decomposed organic fertilizer and 50~60kg of general-purpose compound fertilizer are applied per mu.

The pre-flowering flower top dressing is dominated by high-nitrogen compound fertilizer (such as Yunhe 24-11-10 or 30-8-8), and each plant uses 0.5~1.0 kg of fertilizer.

Strong fruit fertilizer can be selected with potassium sulphate compound fertilizer (such as Jia Shili 15-15-15, Yunhe 15-15-15) or high potassium compound fertilizer (such as Yunhe 16-7-19; Jia Shili 18- 7-20 or 20-5-20), generally 0.5~1.0 kg per fertilizer.

Generally, 0.5% urea is sprayed 2 to 3 times before germination. After germination until mid-July: once every 7 days, spray twice the ratio of urea to potassium dihydrogen phosphate at a concentration of 0.3% to 0.5%; after mid-July to the leaves: 2 times phosphoric acid The ratio of potassium dihydrogen to primary uric acid is sprayed at a concentration of 0.3% to 0.5%. About 20 days before the leaves, spray 0.5% borax + 0.5% urea three times.