Almost all living organisms contain 4 main elements: nitrogen, hydrogen, oxygen and carbon. The vital activity of plants, their condition, largely depends on the amount of nitrogen in the soil where they grow. Under natural conditions, soil at different latitudes has unequal nitrogen saturation. The benefits of nitrogen for plants are known even to novice gardening enthusiasts, so providing crops with the proper amount of nitrogen fertilizers becomes an integral element of growing crops.
The climatic conditions of the regions affect the nitrogen richness of the soil. The amounts of nitrogen in the soil type are arranged in descending order:
- Chernozem, powerful and ordinary.
- Podzolic soil.
- Sandy, sandy loam soil.
Most nitrogen (about 5%) is contained in soil humus. The general soil layer is nourished precisely from humus, therefore, the higher the nitrogen content in humus, the richer the soil is in nitrogen compounds. The decomposition of humus upon contact with organisms in the soil occurs slowly; ultimately, plants can receive no more than 1% of the total amount of nitrogen contained in humus.
The plant is able to absorb and assimilate nitrogen in the soil only after completion of the mineralization process caused by microorganisms. As mentioned above, this process takes a lot of time, the amount of which varies depending on environmental factors, such as:
- Chemical properties of the soil itself.
- Humidity level.
- Average air temperature in the region.
- Degree of aeration.
- Etc.
The importance of nitrogen in plant life
Nitrogen plays a fundamental role in the formation of the roots and stem of a plant, so gardeners try to fertilize their crops with nitrogen compounds, especially diligently at the initial stage of development. Nitrogen fertilizer allows the plant to develop leaves and flowers much faster and in greater quantities than plants that are not fertilized with nitrogen.
Most of the nitrogen goes into the formed young shoots and leaves of the plant. As they grow, stored nitrogen moves along the stems from already grown leaves to new ones.
Excessive feeding with nitrogen causes a slightly different effect: the plant begins to accumulate a mass of roots, stems, leaves, but the ripening of flowering and fruits is greatly inhibited, for this reason it is necessary to strictly observe the dosage of fertilizers.
Lack of nitrogen also has an inhibitory effect on growth, but not only of fruits, but of the entire plant organism as a whole. The stems and leaves of plants suffering from nitrogen deficiency look weakened and have a yellowish color. A lack of nitrogen gives rise to a lack of chlorophyll, without a sufficient amount of which the normal absorption of sunlight by the plant is impossible. Poor quality of photosynthesis causes stunted development, weakness of the plant, and yellow leaves and stems.
A plant properly fertilized with nitrogen not only grows faster and produces more fruits, but the quality of the crop also increases due to the increased protein content in them. Nitrogen is contained in all protein compounds; a competent increase in the dose of fertilizing allows you to enrich the crop with useful substances.
An expectedly large harvest can be obtained only by feeding the plants in a strictly limited dosage. Excessive fertilizing with nitrogen, or lack of nitrogen nutrition, will inhibit the development of both individual crop representatives and a low yield as a whole.
Classification of fertilizers with nitrogen
The classification of nitrogen fertilizers contains 5 main groups, divided by nitrogen concentration and additional substances in the composition:
- Nitrate. Characterized by the content of calcium and sodium nitrate.
- Ammonium. Fertilizers containing ammonium sulfate and ammonium chloride.
- Ammoniacal—nitrate. A complex group of fertilizers containing both ammonium and nitrates. One of the representatives of the complex group class is ammonium nitrate.
- Amide. The most common fertilizer of the group is urea.
- Ammonia. A group of fertilizers, liquid in composition. Examples: ammonia water, anhydrous ammonia.
The physical state of nitrogen fertilizers comes in two types: liquid and solid. In gardening, liquid fertilizers are predominantly used due to their efficiency and ease of use. The main component of such fertilizers is ammonia.
The benefits of using nitrogen fertilizers
Enriching the soil with nitrogen fertilizers helps solve most problems with fertility and growth of planted plants.
The main advantages of using nitrogen fertilizers:
- Accelerating the growth of plant organs: stems, roots, foliage.
- Saturation of plants with amino acids at a young age.
- Improving the water balance of the plant.
- Acceleration of mineralization processes of other soil fertilizers added after nitrogen.
- Increasing plant resistance to the external environment and damage.
- Increasing the yield of the entire crop.
Production of nitrogen fertilizers
The process of producing nitrogen fertilizers takes place by mixing two types of gas: hydrogen and nitrogen. Burning coke inside the generating set releases nitrogen abundantly, which is mixed with hydrogen - a product of burning oil or coke.
Mixed gases form an ammonia compound, which subsequently becomes the basis for future fertilizer. Also, during the reaction, another product appears - nitrate acid, from which nitrate fertilizers are produced.
Scope of application and dosage
Almost all crops produce greater yields after nitrogen fertilizers. The only exceptions are legumes, which do not require nitrogen for growth. The rest of the standard set of vegetables and berries for the garden: potatoes, cucumbers, tomatoes, carrots, strawberries, flowers, etc., provide a significant increase in yield after using nitrogen fertilizer.
The generally accepted rate of fertilizer application for different crops is as follows:
Application
Depending on the type of crop and the direction of soil fertilization, the nitrogen composition is dissolved in water: the indicated dosage per 10 liters of water. The resulting solution is applied to the soil, geographically, or over the entire area of the garden.
Characteristics of nitrogen fertilizers
Urea
Urea (urea) – has a high nitrogen content, up to 46%. Available in easily soluble granules, it is one of the most concentrated nitrogen fertilizers. Urea is available in two types - A and B. In gardening, the second type is used, saturated with special additives to increase fertility. The first type is used to feed livestock.
Acid-sensitive plants will require additional neutralization before treatment with urea. Ordinary ground lime is suitable, which must be mixed with urea in a ratio of 10 to 8.
Ammonium nitrate
The nitrogen content in saltpeter is 35%, the composition is easily absorbed by plants, looks like a granular substance, and easily dissolves in water. Nitrate has several minor disadvantages that do not affect the quality of the fertilizer. The composition is vulnerable to moisture, and when liquid gets in it quickly hardens and cakes. In addition, ammonium nitrate should not be heated or mixed with organic compounds - manipulation of the composition can lead to ignition.
Ammonium sulfate
Ammonium sulfate has a significant drawback, resulting in severe acidification of the treated soil. To correct the acidic environment, the composition is diluted with lime, but it must be remembered that slaked lime, like ash, is not suitable for neutralizing acidity. These substances nullify the effect of ammonium sulfate.
The composition contains a mass fraction of nitrogen equal to 17.5%, the standard release form is granulated powder. This nitrogen fertilizer is perfect for soil with high acidity and will make its composition more alkaline. Fertilizer must be protected from moisture during long-term storage.
Anhydrous ammonia
One of the most concentrated nitrogen fertilizers - 80% content. The remaining 20% of the composition is hydrogen. The fertilizer has a pungent odor and requires careful use, being quite dangerous.
Aqueous ammonia
Similar to the previous composition, but with a much smaller proportion of nitrogen, it is a regular solution of ammonia and water.
Liquid ammonia
It looks like a clear liquid with a distinct smell of ammonia. It has the highest concentration of nitrogen of all other analogue fertilizers. Available in liquid form, which is diluted with water when preparing a solution.
The characteristics of nitrogen fertilizers allow you to select the composition for the type of soil: the most nitrogen-rich mixtures are suitable for the poorest soils; to maintain the quality of plants, less concentrated fertilizers can be used.
Video - Nitrogen and nitrogen fertilizers
Signs of nitrogen deficiency in the soil
Nitrogen starvation in plants on soil can usually be determined by the same signs:
- Slow growth.
- Yellow leaves or yellow spots on leaves.
- Red border on the edges of strawberry leaves.
- Slow growth, few shoots and poor flowering and decorative flowers.
- As the whole plant grows, the leaves of the tomatoes become small, and the fruits that set fall off.
- Trees have a hard time surviving cold weather conditions, in some cases the bark turns red and the leaves become pale and small.
The use of any fertilizer implies compliance with the dosage, application according to the rules that can be found on the fertilizer packaging. An overdose, as well as a lack of nitrogen, negatively affects the crops grown. Nitrogen is extremely important throughout the growth and development of a plant, so a gardener who wants to grow a rich harvest will definitely fertilize the soil with nitrogen.
The term “nitrogen-containing fertilizers” usually causes a negative reaction among summer residents who have little experience in growing garden and vegetable plants, as well as among supporters of organic farming. Few people think that “ecologically friendly” manure or bird droppings are organic nitrogen fertilizers, and their excess is no less harmful to human health than the so-called “chemicals”. This article will address questions about what nitrogen fertilizers are and what types of them are used in garden plots.
Nitrogen in plant life
The role of nitrogen and its derivatives in plant life is difficult to overestimate. Metabolic processes at the cellular level occur in plants with the participation of protein, which is a building material for cell division, the synthesis of chlorophyll, trace elements, vitamins, etc.
Nitrogen is a chemical element and an important component of plant protein. With its deficiency, all organic processes in cells slow down, plants stop developing, begin to get sick and wither.
Nitrogen is as important and necessary for all plants as sunlight and water; without it, the process of photosynthesis is impossible.
Most of the nitrogen in bound form (organic chemical compounds) is found in soil rich in humus and waste products of worms (vermicompost). The maximum concentration of nitrogen (up to 5%) was recorded in chernozem, the minimum – in sandy and sandy loam soils. Under natural conditions, the release of nitrogen in a form suitable for absorption by plants occurs quite slowly, therefore, when growing crops, it is customary to use fertilizers containing nitrogen in a form that is easily absorbed by the roots. They contribute to:
- accelerated vegetation of crops;
- elimination of deficiency of amino acids, vitamins and microelements;
- increasing the green mass of plants;
- easier absorption of nutrients from the soil by plants;
- normalization of soil microflora;
- increasing disease resistance;
- increase in productivity.
However, it should be remembered that not only a lack of nitrogen in plants is harmful, but also its excess, which contributes to the accumulation of nitrates in vegetables and fruits. Excess nitrates consumed in food can cause significant harm to human health.
Signs of nitrogen deficiency and excess in plants
The use of fertilizers directly depends on the composition of the soil, its chemical composition, fertility, acidity, structure, etc. Depending on these factors, the required amount of fertilizer is determined and fertilizing is carried out.
Nitrogen deficiency
If the nitrogen concentration is insufficient, this immediately affects the appearance of the plants and their tone, namely:
- leaves become small;
- the green mass is thinning;
- the foliage loses color and turns yellow;
- Leaves, shoots and fruit ovaries die off en masse;
- plants stop growing;
- the appearance of young shoots stops.
When such symptoms appear, it is necessary to fertilize with nitrogen-containing fertilizers.
Excess nitrogen
If the nitrogen content is excessive, all the strength of the plants is spent on growing green mass, they begin to fatten and the following signs appear:
- large, “fat” leaves;
- darkening of the green mass, its excessive juiciness;
- flowering is delayed;
- the ovaries either do not appear or there are very few of them;
- fruits and berries are small and inconspicuous.
Main types of nitrogen fertilizers
Nitrogen fertilizers are chemical compounds containing nitrogen molecules in various forms, used in agriculture to improve crop growth and increase the quality and quantity of crops. Initially, their classification implies division into two large groups:
- Mineral.
- Organic.
Mineral nitrogen fertilizers and their types (by groups):
- nitrate;
- ammonium;
- complex (ammonium-nitrate);
- amide;
- liquid form.
Each group includes its own types of fertilizers, which have different names and special properties, effects on plants and the procedure for fertilizing.
Nitrate group
This group includes fertilizers that contain so-called nitrate nitrogen, its formula is written as follows: NO3. Nitrates are salts of nitric acid HNO3. Nitrate fertilizers include sodium nitrate, calcium nitrate and potassium nitrate.
The chemical formula - NaNO3, is sodium nitrate (another name is sodium nitrate), in which the concentration of nitrogen is up to 16%, and sodium - up to 26%. Outwardly it resembles ordinary coarse crystalline salt and is perfectly soluble in water. The disadvantage is that during long-term storage, sodium nitrate cakes, although it does not absorb moisture from the air well.
By consuming the nitrate component of the fertilizer, plants deoxidize the soil, reducing its acidity. Thus, sodium nitrate and its use on soils with an acidic reaction provide an additional deoxidizing effect.
The use of this species is especially effective when growing potatoes, beets, berry bushes, fruit crops, etc.
Calcium nitrate
The chemical formula is Ca(NO3)2, which is calcium nitrate (another name is calcium nitrate), in which the nitrogen concentration reaches 13%. It also looks very similar to table salt, but is highly hygroscopic, absorbs moisture from the air well, and dampens. Stored in moisture-proof packaging.
It is produced in granular form; during production, the granules are treated with special water-repellent additives. Calcium nitrate copes well with excessive soil acidity, additionally providing a structuring effect. Calcium improves nitrogen absorption processes and has a general strengthening effect on almost all agricultural crops.
Potassium nitrate
The chemical formula is KNO3, it is potassium nitrate, the concentration of nitrogen is 13%, potassium is 44%. Externally it is a white powder with a crystalline particle structure. It is used throughout the season, and especially during the formation of ovaries, when plants need a large amount of potassium, which stimulates fruit formation.
Typically, potassium nitrate is applied to fruiting and berry crops, such as strawberries, raspberries, beets, carrots, tomatoes, etc. It is not used for all types of greens, cabbage, and potatoes.
Ammonium group
Ammonium is a positively charged NH4+ ion. When interacting with sulfuric and hydrochloric acids, ammonium sulfate and ammonium chloride are formed, respectively.
Chemical formula - (NH4)2SO4, contains up to 21% nitrogen and up to 24% sulfur. Externally, it is a crystallized salt that dissolves well in water. It does not absorb water well, so it is stored for a long time. Produced as a by-product of the chemical industry. It is usually white in color, but when produced in the coke industry it is colored in different colors by impurities (shades of grey, blue or red).
Chemical formula - NH4Cl, nitrogen content - 25%, chlorine - 67%. Another name is ammonium chloride. Obtained as a by-product in the production of soda. Due to the high concentration of chlorine, it is not widely used. Many crops react negatively to the presence of chlorine in the soil.
It should be noted that ammonium group fertilizers, when used regularly, significantly increase the acidity of the soil, since plants absorb mainly ammonium as a source of nitrogen, and acid residues accumulate in the soil.
To prevent acidification of the soil, lime, chalk or dolomite flour are added along with fertilizer at the rate of 1.15 kg of deoxidizer per 1 kg of fertilizer.
Ammonium nitrate group
Basic fertilizer. Chemical formula - NH4NO3, nitrogen content - 34%. Another name is ammonium nitrate or ammonium nitrate. It is a reaction product between ammonia and nitric acid. Appearance: white crystalline powder, soluble in water. Sometimes it is produced in granular form, since ordinary saltpeter has an increased ability to absorb moisture and strongly cake during storage. Granulation eliminates this disadvantage. It is stored as an explosive and flammable substance in compliance with safety standards, because it can detonate.
Thanks to the double nitrogen content in different forms, it is a universal fertilizer that can be used for all types of agricultural plants on any soil. Both ammonium and nitrate forms of nitrogen are perfectly absorbed by all crops and do not change the chemical composition of the soil.
Nitrate can be applied for digging in the fall, in the spring when preparing the soil for planting, as well as into planting holes directly when planting seedlings.
As a result, shoots and foliage are strengthened and crop endurance increases. To prevent acidification of the soil, acidity-neutralizing additives are added to the fertilizer - dolomite flour, chalk or lime.
Amide group
Urea
It is a prominent representative of the group, another name is urea. Chemical formula – CO(NH2)2, nitrogen content – not less than 46%. Externally, it is a white salt with small crystals that quickly dissolves in water. Absorbs moisture moderately and, when properly stored, practically does not cake. Also available in granular form.
According to the mechanism of chemical action on the soil, the amide type of fertilizer has a dual effect - it temporarily alkalizes the soil, then acidifies it. It is considered one of the most effective fertilizers, comparable to ammonium nitrate.
The main advantage of urea is that when it gets on the leaves, it does not cause a burn, even at high concentrations, and is well absorbed by the roots.
Liquid fertilizers
Liquid nitrogen fertilizers are characterized by a greater degree of absorption by plants, prolonged action and uniform distribution in the soil. This type includes:
- anhydrous ammonia;
- ammonia water;
- ammonia.
Liquid ammonia. Chemical formula - NH3, nitrogen content - 82%. It is produced by liquefying its gaseous form under pressure. Outwardly, it is a colorless liquid, with a pungent odor, and evaporates easily. Stored and transported in thick-walled steel containers.
Ammonia water. The chemical formula is NH4OH. Essentially, it is a 22-25% ammonia solution, colorless, with a strong odor. Transported in sealed containers under low pressure, it evaporates easily in air. For feeding purposes, it is more suitable than anhydrous ammonia, but its main disadvantage is the low concentration of nitrogen.
UAN – urea-ammonia mixture. These are ammonium nitrate and urea (urea) dissolved in water. Nitrogen content – from 28 to 32%. The cost of these types is much lower, since there are no expensive procedures for evaporation, granulation, etc. The solutions contain almost no ammonia, so they can be freely transported and applied to plants by spraying or watering. They are widely used due to their relatively low cost, ease of transportation and storage, and versatility of use.
Ammonia. Chemical composition - ammonium and calcium nitrate, urea, etc. dissolved in ammonia. Nitrogen concentration – 30-50%. In terms of effectiveness, they are comparable to solid forms, but a significant drawback is the difficulty of transportation and storage - in sealed low-pressure aluminum containers.
Organic fertilizers
Various types of organic matter also contain nitrogen, which is used to feed plants. Its concentrations are small, for example:
- manure – 0.1–1%;
- bird droppings – 1-1.25%;
- compost based on peat and food waste - up to 1.5%;
- green mass of plants – 1-1.2%;
- sludge mass – 1.7-2.5%.
Experts believe that using organic matter alone on a personal plot does not give the desired effect, and sometimes can harm the composition of the soil. Therefore, it is preferable to use all types of nitrogen fertilizers.
How to use nitrogen fertilizers
It should be remembered that these are chemically active substances that can cause severe poisoning if they enter the human body. That is why you should strictly adhere to the recommendations on the dosage and frequency of fertilizing.
Each package contains complete information and instructions for use; they should be carefully studied before processing the beds.
When working with chemicals, you need to use personal protective equipment - gloves, goggles and suits to protect the skin and mucous membranes. When working with liquid forms of fertilizers, you must use a mask or respirator to protect your respiratory tract.
Particular attention should be paid to the storage of fertilizers and under no circumstances should they be used after the guaranteed shelf life and expiration date have expired. If all conditions are met, there will be no unpleasant consequences from the use of nitrogen fertilizers.
Thus, nitrogen fertilizers and their use on a personal plot can greatly increase the yield of crops, increase their resistance to diseases and pests, and also restore the structure and fertility of the soil.
Plants require nitrogen throughout their life cycle. The concentration of this chemical element in the soil is important for the normal development and fruiting of crops. Nitrogen is used to improve soil composition. But the use of fertilizers has its own peculiarities. You should focus on the recommended application rates for specific plants and soil-climatic zones. In the video you can see how to properly dilute fertilizers and apply them to the soil.
How is natural nitrogen formed?
The natural supplier of nitrogen for plants is soil. Up to 95% of this chemical element is found in the soil in the form of organic compounds, such as amino acids, amines, proteins, etc. The highest percentage is achieved - approximately 5% nitrogen, but only 1% of the compounds are in mineral form that is easily absorbed by plants. Mineralization processes (ammonification, nitrification) depend on the activity of microorganisms that process soil organic matter. Other conditions also affect the rate of decomposition of organic matter:
- soil moisture;
- air and ground temperature;
- physical and chemical composition of the soil (acidity is important);
- aeration;
- air nitrogen nutrition.
The combination of all factors affects the concentration of nitrogen in humus and the total reserves in the soil. Nitrogen-rich and nitrogen-poor soils can be identified by their type. The most total nitrogen is in chernozem (up to 15 t/ha) and peat bog soils (up to 20 t/ha), and less in sandy soils (about 2 t/ha).
Why do plants need nitrogen?
Nitrogen is necessary for plants at all stages of its development: the chemical element is involved in photosynthesis, in the formation of cell nuclei, alkaloids, lipoids and the synthesis of protein substances. Seeds, buds, leaves, roots, and stems of plants contain nitrogen. During the growing season, it is important for the collection of green mass - young leaves and shoots. From the vegetative organs, after flowering and the formation of the ovary, nitrogen compounds move to the reproductive organs. There the compounds are converted into proteins.
Attention! An excess of nitrogen leads to its accumulation in all organs of the plant. The process is accompanied by violent growth of green mass to the detriment of fruiting: ripening time increases, productivity decreases, and the quality of the fruit deteriorates.
Plants must receive sufficient levels of nitrogen for normal development.
Plants that receive sufficient nitrogen nutrition are characterized by good yield and fruit quality. They contain more biologically valuable protein with amino acids (alanine, glutamic acid, histidine, lysine, legumin, etc.).
Signs of nitrogen starvation of plants
To ensure normal conditions for the development of cultivated plants, organic and mineral nitrogen fertilizers are applied to the soil. Not all plant groups are equally demanding of nitrogen. Its deficiency is determined by the following criteria:
- yellowness of leaves (or the appearance of large yellow spots);
- delayed growth and development;
- small leaves;
- depletion of the plant;
- low yield.
Nitrogen deficiency in plants manifests itself in yellowing leaves (or the appearance of yellow spots)
Signs of nitrogen starvation in plants (examples):
- Trees. They do not tolerate winter well; there is weak branching, shredding and dropping of fruits. Pome crops (apple trees, pears, rowan, serviceberry, quince, etc.) have small, pale leaves; stone fruits may have reddened bark of the branches.
- Strawberry, Victoria. Reduced formation of shoots, yellow (even red) border along the edge of the leaf.
- Beet. Slow growth, yellowing and rapid death of lower leaves.
- Tomatoes. Noticeable growth retardation, shredding and.
- Roses. Slow growth of shoots, poor lignification, weak flowering.
- - up to 1% (horse - 0.3-0.8%, pork - 0.3-1.0%, mullein - 0.1-0.7%);
- humus - up to 1%;
- droppings (bird, pigeon, duck) - up to 2.5%;
- compost + peat - up to 1.5%;
- household waste - up to 1.5%;
- green foliage - up to 1.2%;
- green mass - up to 0.7%;
- lake silt - up to 2.5%.
Natural nitrogen fertilizers: manure, humus, compost, peat, litter
Organic nitrogen fertilizers inhibit the accumulation of nitrates in the soil, but use them with caution. The application of manure (compost) to the soil is accompanied by the release of nitrogen up to 2 g/kg for 3-4 months. Plants easily absorb it. It is not recommended to fertilize root crops with fresh manure; humus and good compost are better for them. The amount of humus introduced is calculated based on the concentration of nutrients in it. Thus, 1 ton of half-rotted fertilizer contains 15 kg of ammonium nitrate, 12.5 kg of potassium chloride and the same amount of superphosphate. On the contrary, cucumbers react positively to soil fertilized with manure. It is enough to apply 8 kg/1 m2 of natural fertilizer.
Types of nitrogen fertilizers
Mineral nitrogen fertilizers, which are produced for gardening and agriculture, are conventionally divided into 5 groups:
1. Amide:
1) (urea) with a nitrogen content of 46%. Available in granular form. It is applied under the soil before sowing. Recommended for neutral soils;
2) calcium cyanamide (N - 20%) - alkaline fertilizer for acidic soils. Used before sowing. It is used as top dressing in early spring and autumn under the soil. Insoluble in water;
2. Ammonia:
1) anhydrous ammonia (N - 82.3%) - liquid. Used for basic application and fertilizing. It is applied deep under the soil before sowing and;
2) ammonia water (N – 20.5-46.2%) - solution. Apply in spring and autumn under the soil (up to 10 cm);
3. Ammonium:
1) ammonium chloride (N - 24-25%) - water-soluble powder. Due to the high chlorine content, it is recommended to apply in the fall;
2) ammonium sulfate (N - up to 21%) - neutral salt. Without fear of soil acidification, it is used on chernozems and semi-desert soils, with caution on red soils, yellow soils, gray forest, brown, soddy-podzolic soil types (preferably in combination with fluorine);
4. Nitrate:
1) sodium (N - 16.4%) and calcium (N - up to 15.5%) nitrate - colorless crystals for fertilizing and main application before sowing. Recommended for acidic soils;
5. Double complex:
1) ammonium nitrate (nitrogen up to 34%) - nitrate-ammonium form. Universal composition. Suitable for any soil and crops. It is applied during sowing, fertilizing and main application;
2) combined fertilizer UAN (urea + ammonium nitrate) with 28-32% nitrogen. Solution for basic application and fertilizing for all crops.
Application of mineral nitrogen fertilizers to the soil
Advice. If the soil is neutral or alkaline, it is better to fertilize and feed with ammonia forms of nitrogen. If the soil acidity is high, use nitrate forms of fertilizers.
Complex three-component mixtures are considered universal fertilizers. The formula N+P+K (nitrogen+phosphorus+potassium) is suitable for all soil and climatic zones, any application methods and any plants. Popular compositions: azofoska, ammophoska, diammofoska. All of them consist of these three elements. They differ in the concentration of components, the method of their preparation and the form of absorption by crops.
Nitrogen fertilizer application rates
General nitrogen standards for gardening and horticulture:
- main application - 0.6-0.9 kg/100 m²;
- top dressing - 0.2-0.3 kg/100 m².
Fertilizer rates for crop groups (using the example of ammonium nitrate):
- vegetables (peas, beans, beans), aromatic herbs, ornamental plants (azalio, mololololo, cosmos, poppy, etc.) with low demands on the nitrogen content in the soil - 0.8 kg/100 m² is enough;
- vegetables (spinach, lettuce, sorrel, Chinese cabbage, early potatoes, radishes), fruit (pear) and ornamental crops (daisies, primroses, bulbs, juniper, etc.) with moderate nitrogen consumption - maximum 1.5 kg/100 m²;
- vegetables (tomatoes, carrots, cucumbers, root parsley, beets), fruits and berries (apple trees, gooseberries, currants) and annual ornamental crops with an average nitrogen consumption of up to 2 kg/100 m²;
- vegetables (zucchini, peppers, potatoes, eggplants, cabbage, rhubarb, pumpkin), fruits (cherries, blackberries, plums, raspberries, Victoria) and ornamental crops (cloves, lilac, dahlia, rose, peony, nasturtium, phlox) with high nitrogen consumption - up to 2.5 kg/100 m².
For other fertilizers, the norms can be determined taking into account the percentage of nitrogen content in them.
Nitrogen fertilizers significantly increase the yield of vegetable and fruit crops. If plants are provided with sufficient nitrogen nutrition, then you can count on a good harvest. Nitrogen is an important element that regulates protein synthesis and improves nutrition and absorption of nutrients. With a sufficient amount of nitrogen, plants not only develop organically, but also bear more fruit. Nitrogen can affect the quality and taste of fruits, improves their preservation and resistance to various fungal and bacterial pests.
Nitrogen fertilizers come in organic and inorganic types, liquid and dry. The main substance from which these agrochemicals are made is ammonia. Most often, this type of fertilizer is synthesized in the form of a crystalline powder, but liquid nitrogen-containing chemicals can also be found.
Crystals of nitrogen-containing chemicals dissolve well in water, but are practically not absorbed by the soil, which is why this fertilizer should be applied to the soil in the spring and summer. In the fall, in most cases, the use of nitrogen chemicals is impractical. It is also worth noting the very high ability of crystals to absorb moisture, which requires special conditions for storing this substance.
Inorganic nitrogen fertilizers can be divided into several types, depending on the form of nitrogen contained:
- liquid types of agrochemicals;
- ammonia type;
- in the form of nitrates (salts of nitric acid);
- amide type;
- combined types.
Fertilizers in liquid form
Anhydrous ammonia. This is the most concentrated substance, which does not contain ballast substances. It has no color, actively reacts to the ambient temperature, and therefore requires special storage conditions. During production, it is sealed in an airtight container, since the liquid is pumped under pressure, which is why it is divided into two forms - liquid and gaseous. Quite aggressive to some types of metals and alloys, it is not recommended to store in zinc and copper vessels. Due to the high concentration of ammonia, the fertilizer is toxic; precautions must be taken when working with it. Well absorbed by plants.
It can be used as a fertilizer in the fall, but on lands with a light granulometric composition it is quickly washed away. That is why in such cases it is recommended to apply the agrochemical deeply into the ground in the spring.
Video - Fertilizing soil with anhydrous ammonia
Ammonia water. The fertilizer is sealed in special containers that are under pressure. The substance is not aggressive towards metals and contains a volatile formula of free ammonia, which contributes to large losses of nitrogen during application to the soil. Can be used for autumn, spring application or as top dressing. It is introduced along with water into the deep layers of the soil - 12-15 cm.
Ammonia. The nitrogen content of these liquid chemicals can range from 30 to 50%. Substances are obtained by dissolving various dry granular nitrogen fertilizers in water: ammonium nitrate, urea, etc. These are quite aggressive substances that cause corrosion of ferrous metals and copper alloys.
Ammonia - application to soil
Ammonia types of dry agrochemicals
Used as a basic fertilizer or as a top dressing. The agrochemical does not contain ballast substances, is highly soluble in water, and can be used on both dry and waterlogged soils. At high humidity, it is washed out from the upper layers of the soil. To prevent overdose on a certain area of land, it requires additional grinding before application, as it tends to cake. It can be used together with superphosphates, but the mixture must be enriched with neutralizing components (lime, dolomite, chalk). The neutralizer content should not exceed 15% of the total mass of fertilizers.
Rarely sold in pure form, most often as a mixture with a neutralizer.
Nitrogen in this type of agrochemical is presented in the form of a cation, which tends to linger in the soil. The fertilizer is well absorbed by plants, as it is not washed out during precipitation and melting snow into the lower layers of the soil. Can be used for application to the ground in the autumn-winter period. It has an acidifying effect on the fertile layer; it is recommended to mix it in half with a neutralizer. Can be used as a main fertilizer or as a top dressing. Sold pure or diluted with a neutralizer.
Ammonium sulfate - photo
Ammonium chloride. This type of fertilizer is recommended for use only in the autumn-winter period. It's all about the high chlorine content in the agrochemical formula. Chlorine negatively affects the growth and development of plants. Fertilizer applied for the winter is broken down, and chlorine falls along with precipitation into the lower layers of the soil.
Nitrate types of dry agrochemicals
This type of agrochemical is used as a basic fertilizer. It has an alkaline composition and is suitable for various types of soil. It is well absorbed by plants, but has low fixation in the soil. Helps reduce soil acidity, so it shows the best results on acidic types of soil.
It is also effective on acidic soils, is well absorbed by plants, and is most suitable for root crops, as it enhances the outflow of carbohydrates from the leaves to the roots. It is not applied in the winter, as it is quickly washed out of the soil due to its low fixability.
Amide type dry agrochemicals
Urea. It has the highest concentration of nitrogen and can be used as a basic fertilizer and as a top dressing. It is applied to the soil in the spring, as it is highly leaching. When fertilized, it is quickly absorbed by plants: 2 days after application, an increase in nitrogen in protein compounds is observed.
Combined types of dry ammonia fertilizers
In this type of agrochemical, nitrogen is presented in ammonia and nitrate forms. Since it has an oxidizing effect on the soil, it is not recommended to apply it in its pure form. It is recommended to dilute with lime, chalk or dolomite.
Video - Pros and cons of nitrogen fertilizers (part one)
The amount of nitrogen in various types of fertilizers and storage conditions
Table
| Name | Description |
|---|---|
| The nitrogen content ranges from 21-21.5%. It is stored for a long time, does not accumulate moisture, and has low caking properties. | |
| Ammonia anhydrous | Nitrogen content does not exceed 83%, low caking and hygroscopicity. |
| Ammonium chloride | The nitrogen content is no more than 26%, has moderate caking properties, and weakly absorbs moisture. |
| Ammonia water | The nitrogen content does not exceed 20%. |
| Crystalline ammonium nitrate | Nitrogen content - up to 35%. During long-term storage, it is characterized by high hygroscopicity, poor dispersion and strong caking. |
| Ammonium nitrate granulated | Nitrogen content - no more than 34.5-35%. It strongly absorbs moisture, requires special storage conditions, and has low caking properties. |
| Nitrogen content - no more than 16%, characterized by low caking, moderate hygroscopicity, good dispersibility after storage. | |
| Nitrogen content -16-17%, quickly absorbs moisture, has high caking properties. | |
| Crystalline urea | Nitrogen content - 45-46%, poor dispersion after storage, low hygroscopicity and caking. |
| Urea granulated | Nitrogen content no more than 46%. Non-hygroscopic, low caking and good dispersibility after storage. |
Organic types of nitrogen fertilizers
This type of fertilizer cannot be called effective for large areas. The nitrogen content in poultry droppings ranges from 1 to 2.5%. It is also worth noting that this type of fertilizer is considered toxic.
Homemade fertilizer also contains nitrogen in small quantities - up to 2%, but the compost itself is quite nutritious and useful for the growth of most plants, so its use as a top dressing or base for planting is quite popular and widespread.
What is this fertilizer for?
During growth and development, the plant synthesizes many different proteins that differ in functionality, molecular weight and number of amino acids. Those proteins that are produced during different stages of plant growth are significantly different from those substances that make up the organs and cells of already formed shoots and leaves. It is worth noting that any protein synthesis is accompanied by large losses of energy, which is formed during the process of photosynthesis.
It is nitrogen that provokes the process of photosynthesis in plants, which in turn contributes to faster and higher-quality protein synthesis. The presence of nitrogenous fertilizers in the soil is especially important during the period when plants form stems and leaves. During development, the plant actively absorbs nitrogen from the soil and accumulates it in its organs. As the plant grows, nitrogen can move from aged organs to newly formed shoots and leaves.
After application to the soil, nitrogen fertilizers are almost 70% processed by various microorganisms inhabiting the soil. There is also a leaching of salts and nitrates from the upper layers of the soil. After the bacteria die, the plants begin to absorb the necessary nitrogen from the resulting mass. No more than 40-50% of the nitrogen from the total applied fertilizer remains for the plants.
How to understand that plants do not have enough nitrogen
A lack of nitrogen has a catastrophic effect on the growth and development of any plant crops. First of all, the process of photosynthesis and respiration slows down, which provokes a delay in growth and formation of shoots and leaves. Also, a lack of nitrogen can cause changes in the shape of leaves, a decrease in the size of inflorescences, and a lack of fruit formation. If plants feel nitrogen deficiency, their leaves change color, become pale, and in particularly difficult cases, chlorosis can be observed.
Most often, nitrogen deficiency is observed in the following types of soil:
- sandy;
- podzolic;
- serozems;
- red soils;
- with a high alkali content.
It is also worth knowing that nitrogen starvation can occur in the following cases:
- fertilizer in the spring was applied to the soil too early and microorganisms that contribute to nitrogen mineralization do not process nitrogen-containing chemicals;
- nitrogen starvation can occur on turfed soil;
- large amounts of precipitation in spring. Excess moisture promotes leaching of nitrogen from the upper layers of the soil.
Signs of nitrogen deficiency in vegetable and horticultural crops
Table
| Name | Description |
|---|---|
| The growth of shoots slows down. The color of the leaves becomes pale, the veins on the back of the leaf become red or burgundy. The roots turn brown, become deformed and quickly die. The inflorescences fall off; if the plant bears fruit, the tomatoes grow very small and rarely ripen to the point of redness. |
| The lower leaves on the shoots become yellow, the stems lose their rigidity and flexibility, and become brittle. The inflorescences fall off; if ovaries appear, the fruits are small in size and pointed at the ends. |
| The growth of stems slows down, the leaves acquire a yellowish tint. The lower tier of leaves may die, the upper tier has small foliage. Most often, nitrogen starvation is observed during the flowering and budding period of the crop. |
| With a lack of nitrogen, the leaves turn yellow and gradually begin to die. |
| The plants experience growth retardation and the bulb does not form. The green arrows begin to turn yellow at the tips. |
| The heads do not form, the leaves take on a reddish tint. |
| The root crop turns pink and does not develop. Ground leaves become smaller, turn yellow and fall off over time. |
Nitrogen overdose
With an overdose of nitrogen, plants begin to develop green mass, but the reproductive organs completely stop growing. Also, a large amount of nitrogen can burn the root system, causing the plant to wither very quickly.
Video - Pros and cons of nitrogen fertilizers (part two)
The key to the health of garden and vegetable crops is maintaining the balance of oxygen, carbon, hydrogen and nitrogen. But not every type of soil is saturated with the required amount of nitrogen. To solve this problem, nitrogen fertilizers come to the rescue - a substance that contains nitrogen compounds.
The influence of nitrogen on plant growth and development
There is a direct relationship between a plant's lush, dark green foliage and the amount of nitrogen it needs. And this relationship is photosynthesis. Chlorophyll plays an important role in the process of plant photosynthesis. Nitrogen is the main component of protein, which is involved in the formation of chlorophyll.
The nitrogen reserve is contained in the soil (humus), amounting to about 5%, depending on the climate zone. The most nutritious soil is considered to be the one with the most humus. But even if the soil is very rich and fertile, only 1% of nitrogen will be available to the plant. This is due to the fact that the process of humus decomposition and the release of mineral salts is very slow. At the same time, in the spring, during the period of active growth and development, garden crops are most in need of nitrogen. Its deficiency can lead to a decrease in the growth and development of horticultural crops. To prevent such a situation and ensure proper plant growth, it is necessary to provide them with additional nitrogen fertilization.
Organic fertilizer, which will contain nitrogen, can be obtained independently using a compost pit and plant waste. Plants such as clover and lupine contain 0.4 - 0.7% nitrogen, and green foliage contains 1%, bird droppings (chicken, pigeon, duck) and manure.
But before the nitrogen in organic fertilizers transforms into a mineral form that will be available for plant nutrition, it will take time. If you need to fertilize faster, you should use commercially produced nitrogen fertilizer. Popularity of industrial mineral fertilizers due to their effectiveness and ease of use. There are several main groups:
- nitrate fertilizers: sodium nitrate, calcium nitrate;
- ammonium fertilizers: ammonium chloride, as well as ammonium sulfate;
- ammonium nitrate fertilizers: a complex group of nitrogen-containing fertilizers, such as ammonium nitrate;
- amide fertilizers: urea;
- liquid fertilizers: anhydrous ammonia and ammonia water.
Sodium nitrate (sodium nitrate)
Grayish or yellowish powder, easily soluble in water and containing 16% nitrogen. Sodium nitrate is produced by crystallization using natural deposits or ammonia of synthetic origin. Sodium nitrate– an alkaline fertilizer, so it is more effective to use it on acidic soils.
Do not use on soils oversaturated with sodium. It should be used during planting and fertilizing; it is quickly absorbed by plants. Sodium nitrate is actively used during spring feeding of beets, potatoes, fruits and berries, and ornamental crops. It is advisable to exclude application in the fall, as there is a possibility of leaching of nitrogen from the soil. Does not cake during storage.
Calcium nitrate (calcium nitrate)
Available in large pearl-colored granules or in crystalline form. The granular form is more popular since it does not spray during use. In nitrate form, it contains 15-17% nitrogen. Contains calcium nitrate– calcium - 19% and nitrogen - 13%. Calcium nitrate, if recommendations and dosages are followed, has a positive effect on crop yields and has no harmful effects on humans. Despite the fact that saltpeter contains nitrogen, it does not oxidize the soil, so it is used on different types of soil. With regular use, it improves the properties of acidic soil.
Calcium, which is part of calcium nitrate, ensures complete absorption of nitrogen, promoting the development and growth of the crop. Calcium accelerates the germination of seeds and tubers, increases plant immunity and winter hardiness, strengthens the cells and root system.
Ammonium sulfate (ammonium sulfate)
Available in white or gray crystalline form, it is easily soluble in water. Contains about 20.5% nitrogen and is suitable for both fertilizing and main application. Contains ammonia nitrogen, which is fixed in the soil, so the most suitable soil is light, permeable. It should not be used on neutral and slightly acidic soils, since ammonium sulfate tends to acidify the soil. Optimal for feeding heathers, rhododendrons and other inhabitants on acidic soils. Does not cake during storage.
Ammonium nitrate
Available in white granular form with a nitrogen content of about 35%. It is used both as an auxiliary feeding and as a main fertilizer. Nitrate is less effective on very moist soil, since it is a ballast-free substance and can be washed into groundwater. Therefore, its main area of use is– soil with low moisture levels. Ammonium nitrate, when used regularly, increases the acidity of the earth; to eliminate this, neutralizing substances are used.
Store fertilizer in a dry place, as it tends to absorb moisture and cake. If before use it is discovered that saltpeter has formed into large stones, then they need to be broken to ensure uniform distribution of the fertilizer.
Currently, pure saltpeter is practically not found on sale; it is mainly included in mixtures. The most suitable mixture there will be one where the content of ammonium nitrate does not exceed 60%, while the neutralizing substance is 40%. This feeding ratio contains 20% nitrogen.
Urea (urea)
Concentrated fertilizer with a nitrogen content in amide form of about 46% and easily soluble in water. It is more effective to use urea for fertilizing in the warm season on neutral soils. Because the nitrogen contained in urea is poorly absorbed by plants, since it is necessary for it to go into mineral form, and the transition process depends on the temperature and acidity of the soil.
Fertilizer is used for foliar feeding, thanks to its gentle effect on the leaves of the plant. It is also used for spring application before planting. It is advisable to use urea in liquid form, this method will allow the fertilizer to be evenly distributed in the soil; in the case of a high nitrogen concentration, burns to the plant are possible.
Liquid ammonia
There are two types of liquid ammonia: in the first, ammonia content is 20-25%, in the second – 16-20%. Nitrogen content – 82%. During the fertilization process, it requires embedding 8 cm into the soil, otherwise it will evaporate. Liquid fertilizers have a number of advantages:
- low cost;
- plants absorb liquid fertilizers well;
- uniform distribution over the entire treated area;
- longer exposure period.
But many gardeners and gardeners are stopped by such points as:
- transportation and storage (it is not recommended to store at home);
- liquid fertilizers burn the leaves;
- The fertilization process requires special equipment.
Complex
In spring, during the period of active growth, the plant needs not only nitrogen, which promotes the formation of foliage, but also other substances and components that help growth and development. Namely:
- phosphorus helps the plant with the ovary, increases the winter hardiness of the crop;
- potassium improves immunity, thereby making plants more resistant to various diseases and negative natural phenomena.
Each plant has its own needs
It is necessary to understand which crops require high nitrogen content in the soil and which do not. With nitrogen deficiency, the plant slows down and the foliage turns yellow. Ensuring the correct dose feeding, we help the plant to develop properly, form healthy foliage, and also accumulate the required amount of protein in the fruits.
But if these fertilizers are used excessively and exceed the needs of the crop, then all the plant’s forces will go into the foliage, which will negatively affect flowering, ovary and ripening of fruits. Excess nitrogen causes foliage burns. Subsequently, the death of the foliage and then the root system itself.
So, garden and vegetable crops are divided into four groups, each of which needs its own specific amount of nitrogen.
First group. This group is characterized by a high need for nitrogen both before planting (sowing) and during the growing season. The recommended dose is at least 25g. ammonium nitrate, taking into account the planting area - 1 sq. m. If you plan to use other types of fertilizer, then their amount should be adjusted, taking into account the nitrogen content. The first group of crops includes:
- fruit trees and shrubs: plum, blackberry, raspberry, cherry, strawberry;
- vegetable: pumpkin, peppers, rhubarb, zucchini, eggplant, potatoes, cabbage;
- decorative crops: peony, balsam, rose, dahlia, nasturtium, carnation, lilac, paniculata phlox and others.
Second group. Crops included in this group require an average nitrogen content. The recommended dosage for a complete diet is 20 grams. ammonium nitrate per 1 sq. m. landing area. The group includes:
- fruit and berry crops: currants, apple trees, gooseberries;
- vegetable: beets, tomato, cucumber, garlic, carrots, parsley, corn;
- decorative: most annual flowers, delphiniums.
Third group. This group is characterized by moderate requirements for nitrogen content. Recommended 15 gr. ammonium nitrate per 1 sq. m. landing. The crops of the third group include:
- fruit trees: pear;
- vegetables: radishes, onions, early potatoes;
- decorative: bulbous species, saxifrage, daisy, juniper, primrose.
Fourth group. Plants included in the group require a minimum nitrogen content, namely 7-8 grams. saltpeter per 1 sq. m. landing. The fourth group of crops includes:
- vegetable: beans, aromatic herbs, peas;
- decorative: Japanese azalea, young, rhododendron, heather, purslane, Erica, oriental poppy and others.
Basic rules for using nitrogen fertilizers
The correct dosage and regular, timely use of nitrogen fertilizers have a beneficial effect on the development and growth of garden and vegetable crops. The required amount of fertilizer is calculated based on the soil, the plant itself and the season. But there are also basic rules for using fertilizers:
A plant that consumes the required amount of nitrogen grows well and has healthy dark green foliage. As well as balanced and regular nitrogen nutrition contributes to a high-quality harvest.