Application of fertilizers for winter wheat. What fertilizers are needed for winter wheat

An important step in growing winter wheat is the competent selection and application of fertilizing. Autumn fertilizers have a pronounced prolonged effect and are designed to support plantings in winter, provide them with nutrition until spring, and protect them from diseases. Spring fertilizing stimulates the growth and development of wheat and has a beneficial effect on the harvest.

Wheat cultivation

Winter wheat grows on different types of soil, but produces good yields only on fertile soils with an acidity level of 6-7. A powerful root system allows the crop to actively absorb moisture in the spring and begin active growth before the onset of summer heat. A long growing season makes it possible to more productively use nutrients from the soil, including organic matter.

Wheat greatly depletes the soil, and therefore requires timely application of fertilizers. For example, to obtain a yield of 10 centners per hectare, you will need to add 35 kg of nitrogen, 12 kg of phosphorus and at least 20.5 kg of potassium. There are simply not so many nutrients in the soil, and therefore the amount of harvest directly depends on the fertilizers applied.

Do not forget that their quantity must be strictly dosed. If the proportions between macroelements are not met, this will affect the productivity of the crop and the quality of the finished product. In addition, it will be more difficult for wheat to resist pests and diseases.

Feeding in autumn

Fertilizers for winter wheat should include a full range of macroelements, as well as essential microelements and vitamins. The main role is played by nitrogen, on which the growth and development of the crop depends. Phosphorus improves the structure of the soil, facilitates the process of nitrogen absorption, and has a positive effect on the formation of ears. Potassium takes part in intercellular metabolism and is responsible for protein synthesis.

Nitrogen

Wheat needs this macronutrient throughout the growing season. But you should not exceed the application dosage, especially in the autumn. Otherwise, the crop will begin to grow and will not be able to fully prepare for winter. Weakened wheat may not survive the cold season or die from disease.

Nitrogen is introduced in several stages, starting in the fall. The amount of application is determined by the type of soil. Before winter, saltpeter is usually applied (50 kg per hectare), and in the spring urea can be used.

Phosphorus

The macronutrient is also necessary throughout the development of wheat. Autumn application increases the frost resistance of the crop. But phosphorus is needed most of all at the stage of transition into the tube. This element regulates the process of accumulation of sugars, which has a beneficial effect on the taste characteristics of mature grains.

Phosphorus decomposes in the soil for quite a long time, and therefore they begin to add it in the fall, embedding it in the ground to the depth of a spade bayonet. Cereals absorb this element only at +15 degrees and sufficient soil moisture. For winter wheat, any type of Superphosphate is suitable at a dosage of 200 kg per hectare.

Potassium

The mineral is also characterized by a long period of decomposition. Wheat will have time to absorb some of the substances before winter, the rest in the spring. Potassium is required by plants during the period of growth, flowering, tube formation, and heading. It also helps the root system gain strength in the fall and favorably endure the winter cold.

Potassium prevents lodging of spikelets and improves the taste of grains. This element is applied to a depth of 20 cm. In most cases, potassium chloride and potassium salt are used (up to 200 kg per hectare).

Microelements

The crop's need for a specific microelement is determined by the type of soil. Virgin soil and forest soil are deficient in boron, and chernozem requires the addition of zinc and manganese. For all types of soils, add sulfur and calcium.

If the soil is too acidic, dolomite flour is added at the very beginning of autumn. With a lack of magnesium, phosphorus is poorly absorbed, photosynthesis slows down, and therefore this microelement must be added to different types of soil.

Organic

Typically, winter wheat is planted 2 years after adding organic matter. Manure is not placed directly under this crop. The exception is very poor soils, with a humus percentage below 2. The application dosage in this case is up to 40 tons per hectare. To improve the soil on chernozems, 17 tons per hectare is enough. Manure is spread and plowed in the fall.

Fertilizing in spring

This period is unthinkable without the application of nitrogen fertilizers, since the seedlings need to be given nutrients for rapid growth. Already at the end of March, at air temperatures above +5, urea or saltpeter is added. The only difference between these fertilizers is the rate of decomposition: nitrogen from nitrate gets into the soil faster than from urea.

Nitrogen

A comparative analysis of urea and ammonium nitrate showed: with the surface method of application in early spring, the effect of both types of fertilizer was approximately the same. Nitrate is more suitable for chernozem, highly alkaline soil, and urea is more suitable for wood-podzolic soil.

Urea is used during bush formation, during flowering, tube formation, and heading. If it is applied to the soil, the optimal dosage is 0.15 tons per hectare. After scattering, the soil is thoroughly shed so that the substance is completely dissolved and absorbed into the soil.

If used in the form of a solution, then different concentrations of the composition are needed at different periods: in early spring and during flowering - about 20%, when the tube is formed - 11%, when the first spikelets appear - 7%. The use of solutions is most effective during droughts, when the cereal crop experiences an acute lack of water. Special equipment is used in the fields to apply liquid fertilizer.

Foliar feeding with urea gives maximum results when applied before rain. It can be combined with insecticides designed to protect the crop from pests.

Fractional application of nitrogen-containing fertilizers during the growing season can increase the yield of cereal crops and improve the quality of grain, especially the content of vegetable protein in it.

Note. Foliar feeding of cereal crops with urea makes it possible to obtain dense, heavy grains, as well as double their quantity. Urea does not harm plants and does not cause leaf necrosis, and therefore its use is much preferable to the use of other nitrogen-containing fertilizers.

Do not forget about the late spring application of mineral fertilizers, which help to increase not only the protein in the grains, but also the raw gluten.

Phosphorus

Thus, wheat needs phosphorus for more complete absorption of nitrogen from fertilizers. Without it, protein production begins to delay. In addition, phosphorus accelerates the ripening phase of the ears. With its deficiency, flowering and ripening are delayed.

It blocks the harmful effects of aluminum on extremely acidified sod-podzolic soil. Its maximum quantity is observed during the period of emergence, but during the growth of wheat its reserves are significantly depleted. Phosphorus is needed most during tubing, flowering and spikelet formation.

With a deficiency of this macronutrient, the leaves begin to turn reddish and gradually dry out.

Note. Winter wheat is unable to extract phosphorus, which is in a form difficult to assimilate.

Potassium

Stimulates protein synthesis, takes part in the production of carotene and carbohydrates, and has a beneficial effect on the immunity of cereal crops. When it is deficient, the leaves turn blue-green with a characteristic bronze sheen.

Conclusion

Timely application of complex fertilizers for winter wheat will allow you to obtain a consistently high yield on any soil. In addition, good nutrition contributes to the development of stable immunity - the ability to resist diseases and pests.

Preface

In order for winter wheat to please with heavy ears, it cannot be left without attention. Experienced farmers take advantage of every opportunity to apply fertilizer, but it is important to know when to do it.

Required tools and materials

Fertilizing winter wheat in spring - timing

This grain food crop is quite demanding in terms of proper nutrition. At the same time, its root system has a rather low ability to absorb nutrients. Thus, winter crops need nitrogen and phosphorus during the period from the spring tillering phase to heading. Winter crops need potassium in the first period of the growing season and in the heading phase for the development of the root system and enhancing the synthesis of carbohydrates.

So, feeding differs significantly in different periods. In autumn, winter wheat requires very little variety of nutrients, but at the same time it is especially sensitive to their deficiency. A an excess of nitrogen during this period will lead to a significant decrease in carbohydrates in winter crop sprouts and will reduce their chances of survival already in winter. Therefore, you must know what the content of nitrogen and other elements is in the soil. In this case, it is better to use fertilizer mixtures - a product developed individually depending on the condition of the soil.

In the spring, nitrogen again plays an important role, only now it needs to be provided to the sprouts in abundance. Thus, the first fertilizing of winter crops in spring with nitrogen takes place at the beginning of the spring season - in the tillering phase. During this period, the process of vegetation and growth of vegetative organs is resumed. In addition, leaves and stems are formed.

Spring feeding of winter wheat - strictly adhere to the norm

Spring fertilizing of winter crops begins with a very moderate nitrogen fertilizing (30–50 kg/ha). In this case, it is necessary to take into account the doses of nitrogen already applied both before sowing and directly during sowing, because an excess is also fraught with negative consequences. The nitrogen content in the soil can be influenced by climatic conditions, as well as other factors. Nitrogen can be added in the form of ammonium nitrate - this is the most affordable way.

But with this form of surface application, a 2% loss of nitrogen is possible. Therefore, foliar feeding of winter wheat is often replaced by a more effective root method (Buznitsky method), which is implemented using disc seeders. When feeding roots, it is possible to use both urea and other forms of nitrogen fertilizers. You should know that if phosphorus-potassium fertilizers were not applied in the fall, then in early spring they can be applied only in small doses. And best of all in the form of root feeding.

Optimal timing of fertilizing winter wheat

After the initial nitrogen fertilization in early spring, the second one is carried out in the stemming phase. At this time, the formation of flowers and spikelets occurs, which means that increased nitrogen nutrition is necessary. Feeding at this time affects growth processes. Nitrogen use is calculated at 30 to 40 kg/ha. This dose is also calculated using diagnostics. Why calculate anything? And so as not to cause lodging of plants. Because of this phenomenon, you may receive less harvest or significantly reduce its quality.

To prevent lodging, it is necessary to treat winter crops during the tillering period with TUR at a rate of 4 kg/ha.

The third nitrogen fertilization should be carried out in the heading phase - during this period the grains are gaining mass, gluten and protein are formed in them. Of course, farmers also have to take into account the vagaries of nature. It is the precipitation after fertilizing that can negate all your efforts. The feasibility of nitrogen fertilizing when soil moisture is more than 90% is practically zero.

Of course, a lot depends on the amount of precipitation. With timely rainfall, winter crops produce a good harvest. If you want to get high-quality winter crops, then at the first opportunity to go into the field in the spring, you need to inspect all the crops. If winter crops have to endure a cold, protracted spring, then samples must be taken, especially if there is significant damage to the leaf mass.

Biological monitoring of the growth cone can help determine the condition of the plant. You should also pay attention to the appearance of the tissues of the tillering unit. Plants that did not survive the winter or spring frosts well become brown in color - you will not expect a large harvest from them. The situation becomes even more complicated with the onset of late or dry spring. After all, damage caused by spring frosts is usually quite serious and early spring feeding of winter wheat simply will not save the situation.

Early spring or winter fertilizing of winter crops is carried out only with nitrogen fertilizers. It is known that surface fertilizing, without subsequent incorporation into the soil, with phosphorus, potassium and complex fertilizers is unacceptable, since with surface application phosphorus and potassium are fixed at the point of contact with the soil and do not enter the root layer of the soil. They are not able to move down the profile along with precipitation or irrigation water. The effectiveness of fertilizing with nitrogen fertilizers is determined by the following conditions.

1. Moisture availability. The summer and autumn months of 2006 were hot and dry, so the moisture reserves in the soil under winter crops, especially non-fallow predecessors, were small at the beginning of 2007. When moisture reserves are limited, doses of nitrogen fertilizers should be low.

2. Condition of crops. Crops must be sufficiently dense in density, protected from weeds, pests and diseases. Fertilizing should begin with less developed crops, especially those that have not received nitrogen fertilizer since the fall and are already showing signs of nitrogen deficiency - yellowing and dying of the lower leaves, slow growth and development. Well-developed crops need to be fed later so as not to provoke unproductive tillering and accelerated development (especially under irrigated conditions). However, all well-developed crops should be fed in accordance with the diagnosis of nitrogen content in the soil, as they are more productive.

In this case, we ensure high efficiency of nitrogen fertilizing, use the phosphorus of previously applied fertilizers to increase the yield, and additionally obtain an interaction effect in the form of an increase in yield.

If the agrochemical cartogram indicates that the phosphorus content in this field is 1 mg P2O5 per 100 g of soil and less than 1 mg, then fertilizing winter crops with nitrogen fertilizers in this field is impractical.

Therefore, it is necessary to have sufficiently fresh, not outdated and high-quality agrochemical cartograms, which are obtained on the basis of an agrochemical survey of fields, carried out in strict accordance with the accepted methodology, and with the mandatory participation of agronomic personnel of the farm.

At the moment, due to all sorts of reorganizations and lack of funds, mapping is not carried out on time, the maps are outdated or they are lost, and some farmers do not understand the need to have reliable agrochemical cartograms.

As a last resort, using not very old cartograms, you can calculate the content of available forms of phosphorus in the soil today and decide on the advisability of applying nitrogen fertilizers in a particular field. If the maps are lost, you can take copies of them from the archives of the PTC “Crimeasplodorodie”.

If the farm does not have agrochemical cartograms, fertilizers are applied “blindly” and massive errors are made, which cause significant economic losses. For example, when sowing winter crops, phosphates are applied to all fields, including those where the phosphorus supply is high (more than 3 mg P2O5 per 100 g of soil) and phosphorus fertilizers are not needed there. Or they apply nitrogen fertilizing on all areas, including fields with a very low phosphorus content and, therefore, do not receive an increase in yield from nitrogen fertilizers.

5. Nitrogen content in the soil. Due to the lack of moisture in the summer-autumn period, after harvesting non-fallow predecessors, the processes of mobilization of forms of nitrogen available to plants, in particular, the accumulation of nitrates, were suppressed. After stubble precursors, especially when straw was left in the field, the nitrogen present in the soil was absorbed by microorganisms that decompose the straw. This is an inevitable process that requires up to 10-15 kg of nitrogen per 1 ton of straw.

To accurately establish the required rate of nitrogen fertilizer for early spring fertilizing, it is necessary to diagnose the nitrogen supply of plants - visual, tissue, leaf or soil. Soil diagnostics are used most often as the most reliable. It is believed that a meter layer of soil should contain 100-120 kg/ha of nitrate nitrogen (N-NO3) at the beginning of active plant growing season. The indicated amount of readily available nitrogen (and even much more) can be under black fallow under wheat, if the fallow was as it should be according to agrotechnical requirements. But you need to verify this at least in individual typical fields.

For winter crops after other predecessors, the nitrogen norm has to be established by adding the amount of N-NO3 missing to 120 kg/ha. This ensures a yield close to the maximum possible under current weather conditions, but does not guarantee the formation of high-quality winter wheat grain.

To form a high yield of high-quality grain, a meter layer of soil should contain, depending on the planned yield, up to 180-200 kg/ha of N-NO3. Such an amount of easily accessible nitrogen in the soil can accumulate only in black fallow; after other predecessors, it is necessary to add as much nitrogen as follows from the diagnostic results.

A single dose of nitrogen should not be less than 30 kg/ha. If there is a lack of fertilizers, it is better to fertilize a larger area with a smaller dose, if such fertilizing is justified over the entire area (based on the conditions for its effectiveness, for example, if there is a sufficient phosphorus content in the soil, etc.).

Carrying out soil diagnostics is quite a technically complex job and requires good analytical training. As a last resort, you can use calculation methods, for example, the method of the Department of Agrochemistry of the Law Firm "KATU" NAU. Taking into account the conditions of moisture supply, as well as the economic state of farms, for steppe regions we can recommend a nitrogen rate of up to 50-60 kg/ha of nitrogen, for foothill regions - up to 70-80 kg/ha. In irrigated conditions, the rate is increased to 100-120 kg/ha.

6. The best fertilizers for early spring feeding of winter crops with nitrogen are ammonium (ammonium) nitrate and urea (urea). With the correct application of equal doses of nitrogen during the cold season, these fertilizers affect the yield and grain quality of the fertilized crops in approximately the same way. You need to choose one of the fertilizers in which the cost of purchasing, delivering and applying 1 kg of nitrogen will be minimal.

Urea does not dissociate into ions and is not bound by soil. Its ability to migrate with water along the soil profile is somewhat less than that of nitrates that are part of ammonium nitrate. In cold soil (<10°С) карбамид не подвергается аммонификации. Он способен перемещаться вглубь к корням растений так же, как и аммиачная селитра - за счет осыпания в пустоты рыхлого поверхностного слоя почвы, с опускающейся по профилю влагой выпадающих дождей и тающего снега.

In the spring, when the temperature rises above 8-10°C, urea, upon contact with urobacteria in the soil, undergoes ammonification and for this reason significant losses of nitrogen in the form of ammonia are possible. However, incorporating fertilizer into the soil, even by 1.5 cm, sharply reduces losses - at a soil temperature of 6°C they are 0.2%, and at 20°C - 3%.

7. Uniform distribution of fertilizers over the area is of great importance. High uniformity is ensured when applying fertilizers using modern fertilizer spreaders such as Amazon, Sulki, etc., as well as grain disc seeders. Spreaders type 1-RMG-4, NRU-05, etc. need careful adjustment; it is also necessary to prepare fertilizers for application and optimize the distances between passes of the units.

During the cold season, the application of fertilizers to the soil is not required. In March, when the soil reaches physical ripeness, the maximum efficiency of urea and ammonium nitrate is ensured by their local application into the soil using disc grain seeders.

In one of the experiments, with a high accuracy of distribution of 100 kg/ha of nitrogen, the yield of winter wheat when applying ammonium nitrate (Naa) and urea (Nm) was the same - 41.5 c/ha. With insufficient uniformity of fertilizer spreading, the yield in the variant with Naa decreased by 10.1 c/ha (24.3%), and in the variant with Nm - by 15.2 c/ha (36.6%)

Uneven application of fertilizers leads to large losses, especially at higher doses, so it is unacceptable to “save” on their application, since up to 90-95% of the costs are incurred on their purchase, delivery and storage. Urea is a more concentrated fertilizer, so losses from uneven application may be greater.

8. It must be remembered that the lack of mineral nutrition of plants cannot be compensated for by stimulants and plant growth regulators, the use of modern Crystallons, Aquarins, sapropel-based fertilizers and other preparations used in an amount of 2-3 kg/ha. They can be effective against the background of a high supply of plants with basic elements of mineral nutrition.

A. Gapienko, head Department of General and Agronomic Chemistry, Law Firm "KATU" NAU, professor.

Among winter grains, winter wheat occupies a leading position. In 2008-2010 its crops in Russia occupied about 11 million hectares, winter rye 2.1 million hectares.

The main areas sown with winter wheat are concentrated in the European part. New varieties of winter wheat have high potential (up to 200-220 c/ha) and real (80-120 c/ha) productivity. In Western European countries (Germany, Great Britain, Belgium, Holland, etc.), the average yield of winter wheat over the past 5 years is 60-75 c/ha, many farmers annually receive 100-120 c/ha, record grain yields have exceeded 170 c/ha. ha. In general, the world's cereal grain harvest (without rice) already exceeds 600 million tons.

Winter wheat can grow on soils of different cultivation levels, but well-returned yields are possible only on fertile soils. Thanks to its developed root system, it productively uses spring moisture in steppe regions and manages to form good development before the onset of summer drought. The longer growing season of winter wheat, compared to spring wheat, allows it to better utilize nutrients from the soil and organic fertilizers.

Winter wheat is very demanding on soil fertility; it does not tolerate high acidity. The optimal pH value of KCl is 6-7. Wheat absorbs nitrogen and potassium before flowering, and phosphorus - until the grain reaches milky ripeness, and in conditions of high humidity until it reaches milky-waxy ripeness. Wheat consumes the main amount of nitrogen, phosphorus and potassium before heading.

The best for its cultivation in the Non-Chernozem Zone are well-cultivated light and medium loamy soils with a neutral environmental reaction; in the steppe regions - medium and heavy loamy soils. Less suitable for cultivating winter wheat are sandy soils, which, due to low moisture capacity, are not able to provide plants with moisture during dry periods.

Depending on the growing conditions, winter wheat uses 25-30 kg N, 10-14 P 2 O 5 and 20-25 kg K 2 O to form 10 quintals of grain and the corresponding amount of by-products.

Tillering of winter wheat occurs in the fall and continues in the spring after the resumption of the growing season. The key periods in the life and nutrition of winter wheat are autumn tillering before going into winter and early spring resumption of vegetation. In autumn, it needs increased phosphorus and potassium and moderate nitrogen nutrition.

Phosphorus during this period stimulates the development of the root system and increases resistance to adverse conditions. If plants are sufficiently supplied with phosphorus and potassium in the autumn, they develop well and accumulate more sugars, which contributes to their better overwintering. The application of 25-35 t/ha of organic fertilizers before sowing significantly increases the winter hardiness of plants and the intensity of regrowth in the early spring.

The dynamics of nutrient consumption by wheat correlates quite closely with the growth of phytomass. During the autumn growing season, winter wheat consumes a relatively small amount of nutrients (20-25 kg/ha N, 6-8 P 2 O 5 and 15-20 kg/ha K 2 O), however, at a young age it is very sensitive to their deficiency. Winter wheat consumes nutrients most intensively during the period from the spring tillering phase to heading, during the period of rapid growth of vegetative mass. In addition, an optimal supply of nitrogen to plants during this period contributes to the formation of high-protein grains.

Winter wheat, which differs from spring grains in its long growing season (280-320 days), responds well to organic fertilizers. The optimal dose of manure for the Non-Chernozem zone is 30-35 t/ha, for steppe areas - 20-25 t/ha.

The effect of mineral fertilizers on the winter wheat yield is determined by many factors, among which the level of soil fertility, the fertilization of the predecessor, the timing and methods of applying fertilizers are of decisive importance. With an increase in soil fertility, the dependence of wheat productivity on unfavorable weather conditions is significantly reduced. In the Non-Chernozem Zone, on well-cultivated soils, the yield of winter wheat without fertilizers is approximately 25-30 c/ha, and to obtain a yield of 40-45 c/ha, much less fertilizer is required than on soils with low fertility.

Nitrogen fertilization. The need for pre-sowing (autumn) application of nitrogen fertilizers depends on the content of mineral nitrogen in the topsoil before sowing, the precursor and the humus content of the soil. Since before the end of the autumn growing season (going into winter) winter wheat consumes about 20-25 kg/ha of nitrogen, then to satisfy the plant need for nitrogen, taking into account the coefficient of use of soil mineral nitrogen (40-50%), it is required that the mineral nitrogen content in the root layer (0-35 cm) there was at least 40-45 kg/ha. Plants, as a rule, are provided with this amount of nitrogen, taking into account the current mineralization of nitrogen-containing organic matter in the soil, after legume predecessors, when applying organic fertilizers and with a high humus content in the soil. In autumn, nitrogen fertilizers at a dose of 25-35 kg/ha should be applied if winter crops are sown after non-legume predecessors, as well as on sod-podzolic soils with a humus content of less than 2%. On well-cultivated soddy-podzolic and gray forest soils, chernozems and on all soils after early harvested legumes, as well as when applying organic fertilizers, winter nitrogen fertilizers should not be applied in the fall, since excess nitrogen nutrition reduces the winter hardiness of plants. For the rational use of nitrogen, soil diagnostics of nitrogen nutrition is important, which makes it possible to more accurately regulate the doses of nitrogen fertilizers.

High yields of good quality winter wheat can be obtained only if the plants are fully satisfied with the elements of mineral nutrition, and, above all, nitrogen. At the same time, excess nitrogen in the autumn period leads to poor overwintering of plants, and increased nitrogen nutrition in the summer in areas with a humid climate, as well as in rainy weather, causes lodging of wheat during the grain filling period. Lodging of grains leads to the expiration of grain, as a result of intense respiration of the ear and low photosynthesis, a shortage of crops and makes it difficult to harvest. Therefore, when cultivating wheat, it is of great importance to regulate nitrogen nutrition using fertilizers, taking into account soil fertility, precursor and weather conditions.

An important condition for increasing wheat yield and the effectiveness of nitrogen fertilizers is their fractional application. The first fertilizing of winter crops is carried out in early spring when plant growth resumes, as soon as field work can begin. The dose of nitrogen fertilizers is adjusted taking into account the condition of the crops. If the stem density in early spring is more than 1000 pcs/m2, the dose of nitrogen should not exceed 45 kg/ha; the rest of the nitrogen fertilizers should be introduced in the tubing phase, if the stem density is 800-1000 pcs. per 1 m 2 the optimal dose of nitrogen is 50-60 kg/ha, with sparse stems (< 600 шт/м 2) дозу азота можно увеличить на 25-30%.

The best nitrogen fertilizer for early spring feeding of winter crops is ammonium nitrate and UAN, since nitrates quickly penetrate into the zone of active roots, and ammonium adsorbed on the soil surface gradually nitrifies as the temperature rises and thereby prolongs the nitrogen nutrition of plants.

Since the size of the future harvest of grain crops (the number of spikelets and grains in an ear) is laid down at the beginning of the booting phase, complete satisfaction of the plants' nitrogen needs is important during this period. To optimize nitrogen nutrition, at the beginning of booting, plant diagnostics are carried out, on the basis of which the need for feeding during this period is determined. Fertilizing during this period can be carried out with solid (ammonium nitrate, urea) or liquid (10-15% UAN or urea solution) nitrogen fertilizers.

Soil fertility has the greatest influence on the effect of nitrogen fertilizers. As soil fertility increases, the effectiveness of nitrogen fertilizers generally decreases. With sufficient moisture supply to plants, the greatest yield increases from fertilization are observed on light soils with a low content of available nutrients. However, since the large above-ground mass of plants in fields fertilized with nitrogen consumes a lot of water and greatly dries out the soil, the efficiency of using fertilizers on sandy and sandy loam soils without irrigation is on average lower than on loamy soils. In addition, with high doses of fertilizers on light soils, it is necessary to apply fractionally not only nitrogen, but also phosphorus-potassium fertilizers.

Thanks to the differentiated use of nitrogen fertilizers, it is almost always possible to neutralize the influence of predecessors on the yield of winter wheat.

Obtaining high grain yields (> 60 c/ha) in the Non-Chernozem zone by applying fertilizers is limited by lodging, which significantly limits the realization of the potential capabilities of the variety. Lodging of grain crops can be significantly reduced by fractional application of nitrogen fertilizers. To reduce lodging of winter wheat when planning yields above 50 c/ha in many European countries, the entire dose of fertilizer nitrogen is distributed over 2-4 periods: before sowing, fertilizing in early spring, additional and late fertilizing, and the higher the yield, and, consequently, and the dose of nitrogen, the greater part of the nitrogen is transferred to the fertilizer. Doses of nitrogen fertilizers for pre-sowing application are determined based on the fertility of the soil, its granulometric composition and predecessor. When fertilizing in early spring, as noted earlier, the dose is adjusted taking into account the density of the crops and the amount of nitrogen consumed by the plants before the next time of nitrogen application (usually until the plant reaches the middle of its emergence into the tube). Application of nitrogen before sowing and in early spring serves mainly to increase grain yields; nitrogen introduced into the tube midway through the plant affects the yield and protein content of wheat; Late fertilizing during the flowering phase - the beginning of milky ripeness significantly increases the quality (protein content) of grain and does not affect the yield.

Lodging has a great negative impact on the productivity of grain crops. Increasing the dose of phosphorus and potassium fertilizers against the background of high doses of nitrogen does not have a significant effect on the resistance of wheat to lodging. Lodging of cereals depends mainly on the length and diameter of the stem (straw) and the weight of the ear. Increased nitrogen nutrition of plants in areas with a humid climate almost always causes elongation of the straw and a decrease in its diameter, since a significant part of the sugars is used for protein synthesis and less is spent on the formation of mechanical tissues in the straw. Moreover, abundant nitrogen nutrition significantly increases the size of leaves, which in turn causes a lack of lighting, a decrease in the intensity of photosynthesis and the formation of fragile etiolated stems.

Fractional application of the entire dose of nitrogen over 2-3 periods prevents excess nitrogen nutrition and increased tillering of plants, which contributes to the formation of stronger straw.

Depending on the content of mineral nitrogen in the soil before sowing and the predecessor, the optimal dose of pre-sowing nitrogen application for winter wheat is 20-40 kg/ha, and the dose of early spring fertilizing should not exceed 60 kg/ha. On chernozem and chestnut soils, pre-sowing application of nitrogen fertilizers after good predecessors does not have a significant effect on the autumn development of winter crops, therefore the entire dose of nitrogen (30-60 kg/ha) is applied as a top dressing in early spring, and an additional amount of nitrogen intended to increase the protein content of the grain is applied after flowering by spraying the crops with urea at a dose of 30-40 kg/ha.

Perennial legumes and leguminous-cereal grasses with a predominance of the legume component leave behind a large amount (80-160 kg/ha) of organic nitrogen in the composition of crop and root residues, which makes it possible to place winter wheat after them significantly (by 30-40 kg/ha ) reduce the dose of nitrogen fertilizers.

To obtain 45-50 kg/ha of winter wheat grain sown after clover on well-cultivated sod-podzolic soils, it is necessary to apply 80-90 kg/ha of nitrogen fertilizers, and after non-legume predecessors - 110-120 kg/ha. High efficiency of using nitrogen fertilizers can be achieved only if plants are sufficiently supplied with other nutrients and, first of all, phosphorus and potassium. With a low content of available phosphorus in soddy-podzolic soil, high doses of nitrogen (N 120-150) applied against the background of P 60 K 60 did not increase wheat yield due to phosphorus deficiency, while with a higher content of available phosphorus in the soil (100-150 mg/kg), application of N 120-150 and P 60 K 60 provided yield increases of 18.9 and 20.6 c/ha.

According to I. S. Shatilov and A. G. Zamaraev (2005), in a zone of sufficient moisture and during irrigation, fractional application of nitrogen fertilizers in the spring and in the middle of the exit into the tube when planning high yields significantly reduces the lodging of wheat and, thanks to the good absorption of nitrogen, developed to this time by the root system significantly increases the yield and protein content of grain. The increase in yield from the application of nitrogen during the booting phase is primarily due to an increase in the number of spikelets in an ear, the grain size of the ear and the weight of individual grains, while fertilizer nitrogen applied in the spring largely increases the density of plant standing and the growth of above-ground organs. Earlier additional nitrogen fertilizing (at the beginning of emergence) significantly increases the risk of lodging. However, fractional application of nitrogen to grain crops is advisable only when large doses are provided. Since grains necessarily require sufficient nitrogen for early development, crushing small doses only leads to a decrease in yields.

If there is a shortage of funds for fertilizers in the current economic conditions, early spring nitrogen fertilizing with ammonium nitrate at a dose of 20-40 kg/ha is most effective, since the soil does not contain mineral nitrogen for autumn nitrogen nutrition of winter crops.

It is advisable to apply large doses of nitrogen fertilizers (>120 kg/ha) in areas with a humid climate and irrigated conditions in 2-3 doses at the following times: before sowing or early spring, in the middle of booting and to improve grain quality in the heading-flowering phase. More fractional application, even of high doses of nitrogen fertilizers, is ineffective. Since mineral fertilizer nitrogen, which is not required by plants, cannot remain in the soil for a long time, but undergoes biological and chemical processes of intrasoil transformation, a significant part of it is lost as a result of denitrification in gaseous form and leaching of nitrates. Therefore, the timing of application and dose of nitrogen must be adjusted to the needs of plants for a certain growing season.

It is better to carry out late foliar fertilizing with nitrogen using aviation, however, due to the high costs of aerial fertilizing, it is more economical to fertilize using ground equipment. In dry weather, a light wheeled tractor can move over crops up to 30-35 cm high without causing much damage to plants or reducing yield. When sowing seeds, you can also leave the tractor wheel tracks (tramlines) unsown, which are used for the passage of the tractor in all subsequent maintenance activities, weed control and late fertilizing with nitrogen.

The most valuable fertilizer for foliar nitrogen feeding is urea, which, even with a high concentration of the solution, does not cause leaf burns. It is better to carry out additional late feeding with a urea solution (N 30-40) in the morning or evening hours, using boom sprayers.

The effect of nitrogen fertilization on grain quality. Along with increasing yield, nitrogen fertilizers have a great influence on the protein content in grain. Low and moderate doses of nitrogen (30-60 kg/ha) in an area of sufficient moisture do not have any significant effect on protein content. Fertilizer nitrogen applied in early spring in a zone of sufficient moisture in a dose of less than 60 kg/ha is used by plants mainly to increase yield. Higher doses of nitrogen (80-120 kg/ha) increase the yield and protein content in the grain. The protein content in grain with fractional application of nitrogen increases more than with a single application.

In dry steppe areas, where the productivity of winter crops is limited by a lack of water, the application of 30-60 kg/ha of nitrogen increases the yield and protein content of grain. Increasing the protein content of grains is extremely important for the food industry. Since a simultaneous increase in yield and protein (gluten) content in grain is almost impossible to achieve through selection, nitrogen fertilizers can quickly and significantly improve the quality of wheat.

It should be noted that the increased protein content in wheat grain with the application of increasing doses of nitrogen fertilizers occurs mainly due to insoluble gluten-forming proteins, while the content of biologically more valuable soluble nitrogen proteins (albumin and globulin) practically does not increase. It follows from this that increased nitrogen nutrition significantly improves the baking qualities (protein and gluten) of grain, but causes a slight decrease in the content of essential amino acids (including lysine), the proportion of which in soluble proteins is higher than in insoluble ones, therefore the biological value of protein, when late foliar nitrogen fertilizing and the introduction of high doses of nitrogen worsens somewhat.

The best predecessors of winter wheat in the Non-Chernozem Zone are perennial and annual legumes or legume-cereal grasses and annual legumes.

Fertilizer with phosphorus and potassium. Phosphorus and potassium fertilizers, regardless of soil and climatic conditions, should be applied to winter wheat before sowing for the main tillage, leaving a small part of soluble phosphorus-containing fertilizers (10-15 kg/ha P 2 O 5) for application during sowing. Their surface application during the growing season on loamy soils is ineffective, since phosphate ions and K + are sorbed in the application zone on the soil surface and are inaccessible to the root system. Spring and summer feeding of winter crops with potassium and at least phosphorus can be justified only on sandy and sandy loam soils, if there is a danger of their being washed out during autumn application, while on loamy soils feeding with phosphorus and potassium fertilizers during the growing season in all climatic zones ineffective. With low and average content of phosphorus and potassium in the soil, local application of soluble phosphorus and potassium fertilizers is more effective compared to broadcast application and incorporation with a plow with a skimmer, and with increased and high content of available phosphorus and potassium in the soil, methods of applying phosphorus and potassium fertilizers are not play any meaning.

Doses of phosphorus and potassium fertilizers depend on the planned yield, their content in the soil and the supply of plants with other nutrients.

At an average level of mobile phosphorus and exchangeable potassium in the soil, it is quite enough to add 90-120 kg/ha of P 2 O 5 and K 2 O to obtain 45-55 c/ha of winter wheat grain; with a high content of phosphorus and potassium in the soil, doses of phosphorus and potassium fertilizers can be reduced to 60 kg/ha, and if it is very high, you should limit yourself to applying 10-15 kg/ha P 2 O 5 when sowing. The introduction of higher doses of phosphorus and especially potassium fertilizers for grain crops is not economically justified. With a very low content of mobile forms of phosphorus and potassium in the soil (40-70 mg/kg), obtaining high yields without the application of organic fertilizers or preliminary cultivation of the soil is unlikely, even with the application of large doses of mineral fertilizers.

As for the form of phosphorus and potassium fertilizers, they do not have any significant significance for grain crops.

On loamy and clayey soils, due to their good chemical and physico-chemical absorption capacity, phosphorus and potassium can be applied directly to cereals annually or as a reserve for 2-3 years in correspondingly large quantities. It has been established that the reserve application of phosphorus-potassium fertilizers under predecessors does not reduce the yield of grain crops compared to their annual application. However, on sandy soils, mineral fertilizers for winter crops should be applied annually due to possible losses due to leaching.

If you find an error, please highlight a piece of text and click Ctrl+Enter.

With timely sowing, a sufficient amount of moisture and mobile connecting nutrients in the soil, the tillering phase of winter wheat begins 15 days after emergence. Under favorable conditions, the tillering process usually occurs in the fall. Favorable water and nutrient regimes of the soil determine the appearance of friendly and normal shoots and the formation of a developed root system.

germination and shoots - 8%;
tillering - 28%;
output into the tube - 36%;
heading and flowering - 2%;
grain filling -16%.

Phosphorus

Plants are supplied with phosphorus at the beginning of their growth mainly through seed nutrients. The root system of young plants poorly absorbs poorly soluble phosphorus compounds from the soil, so at the beginning of the growing season you need to have a reserve of highly soluble compounds of this element. If we take into account the mass of the arable soil layer (C thousand t/ha) and assume that its moisture content is 25% (although these reserves are not all accessible to plants), then in terms of concentration G.0 - 0.05 mg/l of soil solution the total the amount of the element will be only 0.4 kg/ha.

Under statistical conditions, the transition of H2PO4 ions almost does not occur. Therefore, due to the low solubility of fertilizers and significant distances between their granules in the soil, there is a possibility of positional inaccessibility of phosphorus absorption by plants, since this process occurs only due to diffusion in a small zone around the root. Therefore, line application of phosphorus fertilizers is 4-5 times more effective than spreading fertilizers, since the utilization rate of phosphorus from them reaches 40-60%.

Potassium

Correlation and interaction

Microelements

Boron promotes the synthesis of chlorophyll, affects the formation of generative organs, the development of the root system, especially young roots. It hardly moves from the bottom of the plants to the growing point, that is, it is not reused. A lack of boron in plant nutrition occurs on limed soils and after the application of high rates of nitrogen and potassium fertilizers.

Among cereal grain crops, winter wheat is the most demanding in terms of nutritional conditions. In the development of winter wheat, there are two critical periods of supplying plants with nutrients:

the first - from the emergence of seedlings to the end of the autumn growing season, when plants are very sensitive to a lack of nitrogen and phosphorus;
the second - from the beginning of the resumption of spring vegetation until the emergence of the tube, when the plants are very sensitive to nitrogen deficiency.

Favorable water and nutrient regimes of the soil determine the appearance of friendly and normal shoots and the formation of a developed root system.

In autumn, the bulk of the roots are concentrated in the 0-30 cm layer of soil, and by winter, especially on chernozems, some primary roots penetrate to a depth of 1 m, and secondary roots - up to 0.6 m, and sometimes deeper than 1 m.

Despite the small mass of winter wheat plants in the autumn, an important role in creating optimal conditions for their development currently belongs to the presence and correct ratio between mobile compounds of nutrients in the soil. In the early stages of growth and development (when ear initiation, differentiation and spikelet formation occur), the ratio between nitrogen and phosphorus should be optimal.

Nitrogen

The size of the grain harvest and its quality primarily depend on the nitrogen supply of plants. Typically, grain crops absorb nitrogen in the following dynamics:

germination and shoots - 8%;
tillering - 28%;
output into the tube - 36%;
heading and flowering - 2%;
grain filling -16%.

During sowing of wheat after pure fallow, a significant amount of nitrogen and mineral compounds accumulates in the soil due to microbiological processes. In this case, the fertilizer system should be aimed at neutralizing excess nitrogen nutrition of plants, that is, at enhancing phosphorus and potassium nutrition. Therefore, when drawing up a fertilization system for winter wheat, it is important to take into account the content of mobile connecting nutrients in the soil and the characteristics of the predecessors.

Increased nitrogen nutrition of winter wheat in the early stages of growth and development reduces the yield, since during germination nitrogen retards root growth and predetermines some depression in the initial growth of plants. Increased doses of nitrogen fertilizers during this period contribute to the formation of a loose tissue structure, which accumulates a lot of water in the pre-winter period.

And since the root system develops predominantly in the top layer of soil, this reduces the plants’ resistance to unfavorable winter conditions. In addition, plants can be damaged in the fall by powdery mildew, root rot, and in warm autumn conditions, also by brown leaf rust. Such plants are not resistant to lodging. Therefore, in the autumn, winter wheat needs a small but sufficient amount of nitrogen.

On the other hand, in the case of sowing wheat without applying nitrogen fertilizers after occupied fallow and non-fallow predecessors, the seedlings have a pale green color, which indicates a low chlorophyll content in the plants. The tillering process is reduced or completely stopped when there is a severe nutritional deficiency in wheat.

All vital plant processes are weakened, they do not overwinter well and often die. Therefore, on poor soils or after non-fallow predecessors, special attention should be paid to feeding plants with nitrogen in the fall. Lack of nitrogen during other periods of the growing season has less effect on the yield.

Nitrogen significantly influences the formation of plant productivity elements. Thus, during the tillering phase, a lack or excess of nitrogen, the timing of its application and meteorological conditions can significantly affect the initiation and formation of tillering shoots.

One of the significant features of winter wheat, like other plants, is the continuity of nitrogen and sulfur nutrition. Sulfur, like nitrogen, is a component of protein in plants. In case of its deficiency in the nutrient medium, the restoration and assimilation of nitrogen by plants stops. For diagnostic purposes, it is proposed to consider sulfur deficiency critical when the content of its mobile compounds in the soil is less than 12 mg/kg. The symptoms of sulfur deficiency are almost the same as those of nitrogen, but are more pronounced. Plants are weakly bushy, low-growing, from light green to completely yellow.

Phosphorus

To determine the rate and composition of the main fertilizer, it is important to take into account the influence of nutrients on the winter hardiness of plants. It depends on the accumulation of protective substances since autumn, primarily sugars, biochemical and physiological factors of metabolism (state of protoplasm, content of free amino acids, protein hydrolysis, etc.).

Phosphorus and potassium fertilizers contribute to a greater accumulation of these substances and significantly improve other physiological and biochemical indicators of plant winter hardiness. This explains their high role in the main fertilizer; phosphorus fertilizers work very well on soddy-podzolic soils with an optimal combination of nitrogen and potassium fertilizers. Their effectiveness is reduced on gray and dark gray forest soils due to the sufficient content of mobile phosphates and a deficiency of mineral nitrogen.

In the Forest-Steppe and especially in the Steppe, a condition for insufficient moisture is considered to be the high efficiency of phosphorus fertilizers. This is explained by the fact that southern ordinary and especially carbonate chernozems have a low content of mobile phosphorus compounds.

Under these conditions, phosphorus nutrition of plants improves, which contributes to the intensive development of the root system and generative organs of plants and improves the grain content of the ear, while a lack of phosphorus leads to a delay in the development and formation of spikelets, the stem is formed thin, the root system is weak, the leaves are smaller and darker than ordinary. Reddish or purple leaves are one of the symptoms of phosphorus deficiency in plants. A good supply of phosphorus stimulates the formation of the root system.

In conditions of unstable and insufficient moisture, the effectiveness of fertilizers significantly depends on the depth of their incorporation into moist soil. Phosphorus from fertilizers is best absorbed when they are wrapped in a 10-20 cm layer of soil. Due to the low mobility of phosphates in the soil, transferring part of the phosphorus from the main fertilizer to the top dressing or replacing it with the main fertilizer is impractical even when readily available forms of phosphorus are used.

However, even with sufficiently high reserves of mobile phosphorus compounds in the soil, the concentration of phosphate ions in the soil solution may be insufficient to fully ensure the first stages of growth and development of young plants. Therefore, a mandatory agrotechnological measure on all types of soils is the starting (string) application of phosphorus fertilizers at a dose of 7-20 kg/ha P20. During sowing, you can apply various forms of phosphorus fertilizers - superphosphates, superphosphates, etc.

The use of other forms of mineral fertilizers - ammophos, nitrophoska, nitroammophoska, fertilizer mixtures - is also effective, especially when fertilizers were not applied or were added to the main fertilizer in insufficient quantities, during sowing of wheat after stubble predecessors and crops that are harvested late when in the soil contains few mineral nitrogen compounds. It should be noted that adding more than 300 kg/ha of physical mass of mineral fertilizers to rows reduces the germination of winter wheat seeds. This is explained by an increase in the concentration of the soil solution.

If we take into account the mass of the arable soil layer (C thousand t/ha) and assume that its moisture content is 25% (although these reserves are not all accessible to plants), then in terms of concentration G.0 - 0.05 mg/l of soil solution the total the amount of the element will be only 0.4 kg/ha. Under statistical conditions, the transition of H2PO4 ions almost does not occur.

Therefore, due to the low solubility of fertilizers and significant distances between their granules in the soil, there is a possibility of positional inaccessibility of phosphorus absorption by plants, since this process occurs only due to diffusion in a small zone around the root. Therefore, line application of phosphorus fertilizers is 4-5 times more effective than spreading fertilizers, since the utilization rate of phosphorus from them reaches 40-60%.

So, linear fertilizers are used to improve the conditions for plant nutrition with phosphorus at the beginning of the growing season, and most importantly, to provide them with this element throughout the entire growing season.

Potassium

Potassium increases the cold resistance of plants, enhances tillering, and optimal nitrogen-phosphorus-potassium nutrition at the initial stages of wheat development stimulates the growth and deepening of its roots, promotes the accumulation of a significant amount of sugars, which increases plant resistance to low temperatures and spring drought, and reduces the risk of lodging.

The role of potassium fertilizers is best demonstrated on light soils. In general, the areas of effectiveness of potassium fertilizers coincide with the areas of effect of nitrogen fertilizers. Winter wheat reacts least to them on ordinary and southern chernozems. However, potassium fertilizers, albeit in small amounts, must be applied to all types of soil, since potassium helps to increase the winter hardiness of plants and the strength of stems, which is especially important for varieties prone to lodging.

Correlation and interaction

Nitrogen fertilizers work best on soils with low potential fertility and sufficient moisture, where precipitation does not limit the level of yield (soddy-podzolic and gray forest soils), and the period between the collection of the precursor and sowing is insufficient for the accumulation of mineral nitrogen compounds in the soil due to microbiological processes .

In the southern regions, where the period between the collection of the predecessor and the sowing of winter wheat lasts 2-3 months, the semi-fallow content of the soil contributes to the accumulation of mobile forms of nutrients, including nitrogen. In addition, excess amounts of mineral nitrogen may accumulate. This can lead to unfavorable conditions for the plant to overwinter and further growing season. To mitigate the negative impact of excessive one-sided nutrition of wheat with nitrogen, which is especially observed after pure fallow, only phosphorus and potassium fertilizers are applied before sowing.

When sowing winter wheat after corn for silage, stubble and other non-fallow predecessors, nitrogen fertilizers must also be applied next to phosphorus and potassium fertilizers. This is due to the fact that the soil contains a small amount of mineral nitrogen compounds for the initial growth of plants. In autumn, low doses of nitrogen should also be applied in case of late sowing and on poor soils after worse predecessors.

Nitrogen has a positive effect on the winter hardiness of winter wheat only in an optimal ratio with other nutrients, primarily with phosphorus and potassium. Both excessive one-way nitrogen nutrition of plants and its deficiency negatively affect the accumulation of sugars in plants in the fall. In the first case, this is due to their consumption for the synthesis of more complex organic compounds during the period of plant growth, and in the other, to a weakening of the process of photosynthesis and a disruption of the general processes of growth and development of winter wheat in the autumn. In the latter case, the application of nitrogen fertilizers optimizes development conditions and improves winter hardiness of plants.

So, when assembling a winter wheat fertilization system, it is important to consider its growing conditions. In all cases, the advantage of nitrogen nutrition over phosphorus and potassium cannot be allowed. To solve the issue of adding nitrogen to the main fertilizer, there is only one idea: on soils with a low content of its mineral forms (less than 20 mg/kg of topsoil), 20-30 kg/ha of nitrogen mineral fertilizers are applied.

Microelements

Winter wheat responds effectively to the application of microfertilizers. The most important trace elements for it are manganese, molybdenum, copper, zinc and boron. They are applied to the soil along with basic mineral fertilizers, as well as foliar feeding and pre-sowing treatment of seeds with microfertilizers.

Manganese helps to increase the sugar content in plants, thereby ensuring higher frost resistance and winter hardiness, and increases yield. Plants absorb it most from the tillering phase to heading. So, to prevent a significant reduction in yield, it is important to apply manganese to the seeds. Manganese deficiency is observed in soils with neutral and alkaline reactions.

Copper significantly affects the formation of generative organs, the development and structure of plant cells, increases resistance to diseases, lodging, drought resistance, heat resistance and winter hardiness of plants, and promotes better absorption of nitrogen. Its deficiency occurs on calcareous soils, at high temperatures, at high rates of application of nitrogen fertilizers (more than 100 kg/ha).

A lack of boron in plant nutrition occurs on limed soils and after the application of high rates of nitrogen and potassium fertilizers.

Zinc is involved in many physiological processes, promotes the growth of internodes, increases heat resistance, drought resistance and frost resistance of plants, protein content in grain, and plant resistance to disease. Particular attention should be paid to the supply of winter wheat with zinc when applying high rates of nitrogen and phosphorus fertilizers, liming, and low temperatures.

Optimal nutrition of plants with microelements increases the physiological resistance of plants to diseases and pests. Thus, boron and copper increase the resistance of grain crops to brown leaf rust, and manganese increases the resistance to stem and cut rust. Boron, cobalt and manganese - to powdery mildew. Pre-sowing seed treatment with manganese, copper and boron increases the resistance of grain crops to Hessian flies.