Fertilization techniques for growing strawberries

First, the characteristics of fertilizer demand

Strawberry has shallow root system, strong fertilizer demand, large nutrient requirement, and is very sensitive to nutrients. Excessive or insufficient fertilization has adverse effects on growth and development, yield and quality. Nitrogen fertilizer can promote the formation of a large number of leaves and stolons, strengthen vegetative growth, increase fruit and increase yield; nitrogen-deficient leaves will turn yellow, partially scorched and slightly smaller than normal leaves. Phosphate fertilizer could promote flower bud differentiation and increase fruit setting rate. The upper leaves of phosphorus deficiency showed purple spots, and the flowers and fruits were smaller. Potassium fertilizer mainly promotes fruit ripening, increases fruit sugar content and improves fruit quality; potassium deficiency leaves often appear black, brown and dry at the edge, and turn into burns when serious, the old leaves suffer seriously, the fruit is light in color and taste is poor. In addition, strawberries are very sensitive to chlorine, so the use of chlorine-containing fertilizers should be controlled.

2. Fertilization technology

Apply sufficient base fertilizer: strawberry should be fertilized reasonably in the whole growth period to ensure the healthy growth of the plant, and more flowering, fruit setting, large fruit and high yield. Before planting, combined with deep ploughing and soil preparation, 2000-3000 kg of rotten high-quality organic fertilizer and 50-60 kg of potassium sulfate compound fertilizer were applied per mu.

Reasonable topdressing: in order to meet the demand for various nutrients during the flowering and fruiting period, 1015kg compound fertilizer per mu is generally applied from the beginning of strawberry growth to before flowering stage. During the berry expansion period, about 15 kg of high nitrogen and potassium compound fertilizer can be applied per mu; after a large number of strawberries bear fruit, there is a lack of nutrients in the plant. In order to restore plant growth as soon as possible and form new leaves and roots, topdressing should be carried out as needed. The specific amount of fertilizer should be determined according to the amount of fruit harvest, more fruit harvest, less fruit harvest and less fertilizer.

Extra-root spraying: according to the growth situation of strawberry in the middle and later stage, the method of extra-root topdressing (that is, foliar spraying) can be used for auxiliary fertilization. According to the need, spraying potassium dihydrogen phosphate or other foliar fertilizer for 3 times in the middle and later growth period could increase the fruit setting rate, improve the fruit quality, increase the single fruit weight and prolong the fruiting period. In addition, the spraying of foliar fertilizer should be carried out in the evening on cloudy or sunny days, because of the large evaporation at noon, it is easy to cause strawberry fertilizer damage.