What is good about nitrogen fertilization of winter wheat and how is it applied?

Nitrogen starvation of wheat guarantees a loss of 30% of the yield. To prevent such a situation, the volume of the harvest is planned taking into account the nitrogen needs of the cereal, and the lack of nutrition at each stage of development is compensated for by fertilizing. The benefit and efficiency of work depend on the correct choice of fertilizer, dosage calculation and timely action.

Why winter wheat needs nitrogen fertilizers

Nitrogen is part of proteins - an essential element for the growth and development of plants. Photosynthesis cannot occur without it; thanks to it, plants actively gain green mass and are fully formed. Winter wheat is very demanding on soil. Lack of nutrition will affect not only the volume of the harvest, but also the quality of the grain.

Problems with substance deficiency are distinguished according to the phases of cereal development:

• tillering phase - stopping the formation of shoots;
• the booting stage—the cessation of laying new spikelets;
• flag leaf phase - flowers do not form;
• grain filling stage - small grains of low quality.

Clear signs of nitrogen starvation are a signal that part of the crop has already been lost. Such problems will not arise if you calculate the amount of the required substance and apply mineral supplements on time. Winter wheat produces a harvest at each growth phase.

Therefore, the effectiveness of fertilizers depends on several factors:

1. Time. The ideal moment for feeding is when the crop wakes up and does not yet need nitrogen, but is already able to accept and use it.
2. Calculation by phases. Each stage of development has its own nitrogen norm. The deficiency at the tillering stage is not compensated by the excess at the booting stage - the plant’s potential will decrease, and part of the fertilizer will be wasted.
3. Fertilizer form. The choice of nitrogen form and fertilizing method depends on the development phase of the cereal and the condition of the soil.

Against the backdrop of a general decline in land fertility, such fertilizer becomes for wheat a measure of first necessity.

Types of nitrogen fertilizers for wheat

Dry nitrogen-containing products are produced in the form of powders, crystalline and granular mixtures, which are highly hygroscopic. They quickly dissolve in water and are easy to work with. However, such compositions are demanding when it comes to storage conditions—in unfavorable conditions, they lose their flowability and stick together into large lumps. Storage rules for each type are indicated on the packaging.

Reference! Among the entire range, calcium and ammonium nitrate have the highest risk of caking, and ammonium sulfate is the most shelf-stable.

Fertilizers are grouped according to nitrogen forms:

• ammonium group (ammonium sulfate);
• ammonium nitrate (ammonium nitrate, lime-ammonium nitrate);
• nitrate (sodium nitrate);
• amide - urea (urea).

Ammonium sulfate withcontains 21% nitrogen and 24% sulfur. The fertilizer is well stored and does not cake. This is a quickly accessible and sedentary form, therefore suitable for autumn and spring. Suitable for main nutrition and as a top dressing. Do not mix with alkaline products.

Ammonium nitrate with grade “B” — fine-crystalline powder with additives of calcium, magnesium, sulfate and 34% nitrogen content. A universal fertilizer with 2 forms of the element is suitable for all types of soils and different application periods. Ammonium nitrate stimulates the growth of wheat, despite the cold and frozen ground. Nitrogen forms are not washed out of the soil. The product is used for sowing and fertilizing. It is characterized by high demands on storage conditions.

Attention! Ammonium nitrate is explosive. It is important to follow storage rules and safety precautions when working with the material.

Calcium ammonium nitrate contains 26% nitrogen, calcium and magnesium. This complex, complex-action fertilizer does not acidify the soil and is well suited for saline soils. Apply in spring and autumn as a base, and use as top dressing during the growing season of plants.

Sodium nitrate - alkaline composition, which contains 16% of the element. Easy to digest and suitable for acidic soils. Due to rapid washout, it is not used in the fall. For winter wheat it is used as a nitrogen fertilizer.

Urea non-toxic, contains 46% nitrogen. The granular mixture stores well. Due to the movable shape of the element, it is not suitable for autumn planting. The fertilizer does not burn the leaves, so it is used for foliar feeding.

UAN (urea-ammonium mixture) - liquid fertilizer containing 32% nitrogen. Suitable for incorporation into soil and as foliar nutrition.

All compositions are highly soluble in water, but require increased attention to storage conditions.

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Methods of application

The harvest of winter wheat directly depends on the amount of nitrogen that the plant absorbs. In addition to the pre-sowing application of fertilizers, the grain requires proper systemic feeding. It is carried out in two ways:

1. Root - the main and mandatory method in which single-component or complex fertilizers are applied to the soil. When choosing a product, take into account the quality of the soil, the percentage of humidity, weather conditions and the stages of wheat development.
2. Foliar or leafy - an additional quick way to feed through the leaves. To avoid burns, plants are treated in the morning, evening or at night, when temperature not higher than +20°C and taking into account sufficient humidity. A urea solution is suitable for foliar feeding.

Urea combines well with magnesium sulfate and increases the effectiveness of insecticides and fungicides.

Deadlines for depositing

According to the phases of the growing season, cereals absorb nitrogen in certain dynamics:

• germination - 8%;
• tillering - 28%;
• tubing - 36%;
• ear heading/flowering – 12%;
• grain ripening - 16%.

The maximum effect is achieved not by one-time feeding, but by fractional feeding. The main part is applied in the autumn-spring period, the rest - during the growing season, before the start of grain filling.

20% of the total amount of nitrogen fertilizers is allocated for autumn fertilizing. It is carried out with the onset of cold weather, at a temperature of about +10°C. Under such conditions, the soil biota no longer works and nitrogen is well fixed in the soil.

The first early spring fertilizing is carried out on frozen-thawed soil with a fertilizer consumption of 40% of the total mass. This will help the grain wake up and begin to develop faster than the weeds. Ammonium sulfate, UAN or ammonium nitrate would be optimal.

The second spring feeding is given during the tillering period. It is 30% of the total norm.At that time wheat responds well to ammonium sulfate. Another 5-6% is added in the tubing phase. The remainder is used for additional foliar nutrition with a solution of urea with pesticides and fungicides.

Norms

The total amount of nitrogen fertilizers and the optimal way to use them are selected individually. A lack of a substance affects the productivity of the crop, and an excess can change the condition of the soil. The calculation of the norm depends on the plans for the volume of the harvest. For 1 ton of grain, wheat requires 20–25 kg of nitrogen. Accordingly, for a yield of 5 t/ha, about 100 kg of fertilizing will be required. This is the amount of active ingredient for the entire growing season.

Important! Calculations are adjusted taking into account the predecessor crop, the presence of nitrogen in the soil and early application of fertilizers. For example, for a yield of 6 t/ha, taking into account all adjustments, from 100 to 150 kg/ha of fertilizers are applied in stages.

The spring dose is adjusted according to the condition of the crops:

• the stem density exceeds 1000 pcs./m2—fertilizers provide no more than 45 kg/ha, the remainder is added during the booting phase;
• stem density - from 800 to 1000 pcs./m2 - apply 50–60 kg/ha;
• the stem is sparse - the dose of fertilizer is increased by 25–30%.

Fractional fertilizing with nitrogen is completely absorbed, optimizes tillering, promotes the formation of strong straws and prevents lodging of wheat.

How to fertilize winter wheat

It is unrealistic to feed large fields by hand: it will be a long and labor-intensive process. There is special equipment for the procedure: fertilizer seeders, trailed fertilizer spreaders and mounted sprayers.

The equipment is classified according to its purpose:

• for grinding compacted fats (ISU-4);
• trailers for transportation (RUM-8);
• sprayers of liquid compositions (PZHU-5, PZHU-9);
• spreaders of solid mineral fertilizers (RTT-4, NRU-0.5, 1-RMG-4);
• for applying fertilizer to furrows (MLG-1).

Sequence of work:

1. Calculate the dosage and prepare fertilizers: crush compacted fertilizers or make liquid mixtures.
2. Transporting finished material.
3. Using machines, products are applied to the soil or sprayed. The sprayer's working width must correspond to the tramline.

Common Mistakes

At the initial stage of the growing season, winter wheat feeds only from the soil, but later it also requires foliar feeding. Using only one method of plant nutrition is ineffective.

Common mistakes:

1. Incorrect dosage - taking into account the area of ​​the entire field, and not the plantings, will lead to an excess of nitrogen.
2. Incorrect timing - needs depend not on the calendar, but on the dynamics of development according to the phases of the growing season.
3. Increased concentration - a supersaturated solution leads to burns of leaves and roots.
4. Uneven leaf nutrition - it is important that the solution completely covers the above-ground parts of the plants.
5. A “hellish” mixture is a mix of incompatible mineral compounds that will give a toxic chemical reaction.

To ensure that nutrition is as productive as possible, soil analysis is carried out regularly, and mineral mixtures are prepared according to manufacturers’ instructions.

Conclusion

Winter wheat needs nitrogen throughout the growing season. The consequences of its shortage are low yields, small grains of poor quality and even plant death. Systemic nitrogen feeding will help to avoid these problems. Fertilizers are applied to the soil fractionally and in stages, according to the phases of cereal development, and supplemented by foliar feeding. The dosage depends on the condition of the soil and plans for the volume of the crop.