How to Fertilize Strawberries: A Detailed Guide to Fertilization Techniques for Growing Strawberries

1. Fertilizer Requirements

Strawberry roots are relatively shallow, have a strong ability to absorb nutrients, and have a high nutrient demand. They are very sensitive to nutrients, and both excessive and insufficient fertilization can have adverse effects on growth and development, yield, and quality. Nitrogen fertilizer can promote the formation of a large number of leaves and runners, strengthen vegetative growth, increase fruit size, and raise yield; nitrogen deficiency causes leaves to turn yellow, with localized scorching, and they become slightly smaller than normal leaves. Phosphorus fertilizer can promote flower bud differentiation and increase the fruit-setting rate; phosphorus deficiency causes purplish-red spots to appear on the appearance of the upper leaves, and flowers and fruits tend to be smaller. Potassium fertilizer mainly promotes fruit ripening, increases the sugar content of the fruit, and improves fruit quality; potassium deficiency often causes black, brown, and withered areas at leaf margins, and in severe cases they become scorched, with older leaves suffering more seriously, while the fruit is pale in color and poor in taste. In addition, strawberries are very sensitive to chlorine, so the use of chlorine-containing fertilizers should be controlled.

2. Fertilization Techniques

Apply sufficient base fertilizer: Reasonable fertilization throughout the entire strawberry growth period is necessary to ensure robust plant growth, as well as more flowers, more fruit set, larger fruit, and higher yield. Before planting, apply sufficient base fertilizer in combination with deep plowing and land preparation. Generally, apply 2000-3000 kg of thoroughly decomposed high-quality organic fertilizer per mu, along with 50-60 kg of potassium sulfate compound fertilizer.

Rational topdressing: To meet the demand for various nutrients during the flowering and fruiting period, generally from after strawberries begin growing to before the flowering stage, apply 10-15 kg of compound fertilizer per mu as topdressing; if the base fertilizer amount is sufficient, it may be omitted. During the berry swelling stage, about 15 kg of high-nitrogen-potassium compound fertilizer can be applied per mu; after strawberries bear fruit heavily, the nutrients in the plant body become deficient. In order to restore plant growth as quickly as possible and form more new leaves and new roots, topdressing should be carried out as needed. The specific amount of fertilizer applied should be determined according to the amount of fruit harvested: more fruit harvested means more fertilizer applied, and less fruit harvested means less fertilizer applied.

Foliar spraying: According to the growth conditions of strawberries in the middle and late stages, foliar topdressing (that is, leaf spraying) can be used as a supplementary fertilization method. As needed, spray potassium dihydrogen phosphate or other foliar fertilizers 3-4 times on the leaves in the middle and late growth stages, which can increase the fruit-setting rate, improve fruit quality, increase single fruit weight, and prolong the fruiting period. In addition, foliar fertilizer spraying should preferably be carried out on cloudy days or in the evening on sunny days, because the evaporation rate at noon is high and can easily cause fertilizer damage to strawberries.