Fertilization experience of soil testing formula for growing strawberries

1. Characteristics of fertilizer requirement: strawberry growth needs nitrogen, phosphorus, potassium, boron, magnesium, zinc, iron, calcium and other trace elements. Phosphorus is needed in the early stage of growth, nitrogen is needed in the early and middle stage, and potassium is needed in the whole growing period. If the nitrogen deficiency is heavy, the leaves will turn yellow, partially scorched and slightly smaller than normal leaves. When the phosphorus deficiency was aggravated, the upper leaves showed purplish red spots, and the older leaves also had this characteristic, and the flowers and fruits on the plants were smaller than those of the normal plants. The symptoms of potassium deficiency often occur in the newly mature upper leaves, and the edges of the leaves are often black, brown and dry, followed by burns, the old leaves suffer seriously, the fruit is light in color and tastes bad.

2. Fertilization technology: under the medium fertility level, the amount of fertilizer applied per mu during the whole growth period is 3000hm ~ 3500 kg of organic fertilizer (or 450 ~ 500kg of commercial organic fertilizer), 16kg of nitrogen fertilizer, 8kg of phosphate fertilizer and 10kg of potash fertilizer. Organic fertilizer is used as base fertilizer, nitrogen and potassium are divided into base fertilizer and secondary topdressing, all phosphate fertilizer is applied, and chemical fertilizer and farm manure (or commercial organic fertilizer) are mixed.

Base fertilizer: the base fertilizer is mainly organic fertilizer, combined with appropriate amount of chemical fertilizer. Generally, 3000Mu farm manure 3500kg or 450 MUE 500kg of commercial organic fertilizer, 6kg of urea, 15Mel of diammonium phosphate and 6kg of potassium sulfate are applied. Topdressing: topdressing at flowering stage: 10 kg of urea per mu and 6 kg of potassium sulfate. Berry expansion period topdressing: general mu application of urea 11 Mui 13 kg, potassium sulfate 7 Mel 8 kg. Extra-root topdressing: foliar spraying 0.3% urea or 0.3% potassium dihydrogen phosphate for 4 times or 0.3% borax before and after flowering can increase the fruit setting rate and increase the weight of single fruit. Spraying 0.2% calcium sulfate plus 0.05% manganese sulfate (volume 1 ∶ 1) at early flowering stage and full flowering stage can improve yield and fruit storage performance.