Nitrogen determines vegetative growth:
Strawberries have an increased nitrogen requirement during growth and fruit formation. They prefer ammonium nitrate, which is absorbed especially during the vegetative growth period. In cases of high temperatures or low pH, nitrate is preferred by the plant. Sufficient supply is necessary for yield formation, but an excessive nitrogen supply can cause problems such as excessive runner formation, increased susceptibility to disease, or increased sensitivity to low temperature. Nitrogen should always be added by applying topsoil, whereas phosphorus, potash and magnesium can be used for basal fertilization. Row fertilization is optimal for nitrogen application, especially in large row spacing.
Phosphate is important for good root growth:
In order to stimulate root growth in the best possible way, incorporation of phosphate, either in combination with potash or as NPK fertilizer, before setting, is advantageous. In addition, the flowering behaviour is positively influenced by a sufficient supply of phosphorus.
Potassium reduces stress:
Potassium is important for fruit ripeness, fruit colour and sufficient supply to reduce the stress symptoms caused by drought and low temperatures.
Calcium improves fruit quality:
Regular calcium (Ca) applications are recommended, especially on sandy soils. Calcium is used for building cell walls and thus for better fruit strength. Likewise, calcium is necessary for optimal resistance to sodium toxicity and decreased susceptibility to botrytis. Calcium deficiency reduces the lifespan of strawberry plants. Beyond that, a sufficient lime supply supports the soil structure; strawberries are very sensitive to compaction and waterlogging.
Magnesium and trace elements for better durability:
An adequate supply of magnesium (Mg) is important as a component of chlorophyll, needed for photosynthesis. The same goes for copper (Cu). Magnesium and copper also support the shelf life of fruits.