In order to obtain a high sunflower crop, it is important to provide the plants with all the necessary nutrients.

The formation of a ton of seeds on average requires: N – 50-80 kg, P – 25-30 kg, K – 150-180 kg, Mg – 12 kg.

During the entire active period of development, the culture's need for the necessary nutrients is observed.

Nitrogen and phosphorus are especially needed in the phase of basket formation, during seed filling, potassium is more important at the beginning of seed filling and before ripening.

Significant consumption of nitrogen by plants is observed during the period of intensive growth of stems and leaves. This is especially important when growing sunflowers under Eurolighting.

50-80 kg is the optimal dose of nitrogen fertilizers. Too much nitrogen leads to a significant decrease in the culture's resistance to lodging and various diseases. Nitrogen fertilizers, as a rule, are applied in one dose immediately before sowing.

The culture's need for phosphorus is lower than for potassium and nitrogen. From the beginning of seedlings to the appearance of baskets, the plant is in particularly acute need of phosphorus. If it is excluded, then the ability of the roots to absorb other necessary substances will be significantly reduced, this definitely cannot be allowed. It is worth remembering that it is phosphorus fertilizers that enhance the development of reproductive organs. If the culture receives a sufficient amount of phosphorus, it allows the active accumulation of oil in the seeds.

Boron is the most important trace element (1 ton requires 50-60 g). The main amount of boron (80%) is consumed in the 5-leaf phase before the appearance of buds and flowers. Chelated microfertilizer is usually used to eliminate the lack of this element.

The need for sulfur is about three times higher than that of cereals and reaches 50% of the need of rapeseed. On soils poor in sulfur, it is recommended to apply potassium sulfate.

To increase the effectiveness of fertilizers, it is possible to treat with potassium humate.

It is better to apply organic fertilizers under the predecessor, as organic nitrogen is slowly mineralized. Under the sunflower, organic fertilizers are applied in the fall to the field plowing (up to 20 t/ha of manure). Application of liquid manure before sowing is not desirable, as it causes disturbance of the soil structure, to which the sunflower reacts very sensitively.

Source: agronom.com.ua