Fertilizer with low nitrogen content. Description and rules for the application of nitrogen fertilizers. Nitrate types of dry agrochemicals

nitrogen fertilizers- nitrogen-containing substances that are used to increase the nitrogen content in the soil. Depending on the form of the nitrogen compound, one-component nitrogen fertilizers are divided into six groups. They are used in the main method as seed fertilizers and as a fertilizer. The production is based on the production of synthetic ammonia from molecular hydrogen and nitrogen.

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Groups of nitrogen fertilizers

Depending on the nitrogen compound contained, one-component nitrogen fertilizers are divided into six groups:

• ( , );
• (, ammonium chloride);
• Amide ();
• ( , (CAS);

Nitrate fertilizers

Nitrate fertilizers contain in the nitrate form (NO 3 -). This group includes NaNO 3 and Ca(NO 3) 2 .

Nitrate fertilizers are physiologically alkaline and shift the soil reaction from acidic to neutral. In connection with this property, their use is very effective on acidic soddy-podzolic soils. Use on saline soils is not recommended.

Nitrogen fertilizers (by forms of nitrogen)

Ammonium fertilizers are substances containing NH 4 + in the form of an ammonium cation.

These include ammonium sulfate (NH 4) 2 SO 4, ammonium sodium sulfate (NH 4) 2 SO + Na 2 SO 4 or Na (NH4) SO4 * 2H2O), ammonium chloride NH 4 Cl.

The production of ammonium fertilizers is simpler and cheaper than nitrate fertilizers, since the oxidation of ammonia to nitric acid is not required.

all over the world they are used in irrigated agriculture for rice and cotton, especially in areas of excessive moisture, in particular, in the tropics. In Russia, ammonium sulfate has been produced since 1899. It was first obtained in the Donbass, at the Shcherbinsky mine, by trapping and neutralizing ammonia with sulfuric acid, which is formed during coking hard coal. The concept of this method is still used today.

received as a waste product of caprolac. Effective when applied under beets and other root crops due to the presence of sodium. Recommended for hayfields and pastures.

Ammonium chloride (ammonium chloride)

contains a significant amount of chlorine - 67%, 24-26%. Apply under chlorine-sensitive crops (potatoes, tobacco, grapes, onions, cabbage, flax, hemp) as a fertilizer or not recommended. It is possible to introduce ammonium chloride under chlorophobic crops only in autumn and in areas of sufficient moisture. In this case, chloride ions will be washed out of the root layer by atmospheric precipitation.

Ammonium chloride is a finely crystalline powder of yellowish or white color. At 20°C, 37.2 g of the substance is dissolved in 100 m 3 of water. It has good physical properties, does not cake during storage, and is slightly hygroscopic.

Ammonium chloride is obtained as a by-product in the production of soda.

Ammonium nitrate fertilizers contain nitrogen in the ammonium (NH 4 +) and nitrate form (NO 3 -). This group includes ammonium nitrate (NH 4 NO 3), ammonium sulfo-nitrate ((NH 4) 2 SO 4 * 2NH 4 NO 3 + (NH 4) SO 4), lime-ammonium nitrate (NH 4 NO 3 * CaCO 3).

contains nitrate and ammonium nitrogen in a ratio of 1: 1. It is more correct to call this fertilizer ammonium nitrate, but ammonium nitrate is a more common name. This is the most effective one-component nitrogen fertilizers. Ammonium nitrate is a non-ballast fertilizer. The cost of its transportation and application to the soil is much lower than that of other nitrogen fertilizers (with the exception of urea and liquid ammonia). The combination of mobile nitrate nitrogen with less mobile ammonium nitrogen makes it possible to widely vary the methods, doses and timing of ammonium nitrate application, depending on regional soil and climatic conditions and the specifics of agricultural practices for growing crops.

(ammonium sulfate-nitrate, montan-nitrate, lane-nitrate) - a grayish fine-crystalline or granular substance of a grayish color.

Physicochemical characteristics fertilizers allow it to be successfully used in various soil and climatic conditions. Possesses potential acidity.

Lime ammonium nitrate

- granulated fertilizer. The ratio of saltpeter and lime varies depending on the brand of fertilizer. Widely used in Western Europe.

Amide fertilizers

Amide fertilizers contain in the amide form (NH 2 -). Urea CO(NH 2) 2 belongs to this group. Nitrogen in urea is present in organic form as carbamic acid amide. It is the most common solid nitrogen fertilizer. It is used in all application methods, but is most effective for.

Liquid ammonia fertilizers are liquid forms of nitrogen fertilizers. This group includes liquid (anhydrous ammonia) NH 3, ammonia water (hydrous ammonia), ammonia. Production of liquid ammonia fertilizers is much cheaper than solid salts.

contains 82.3%. This is the most concentrated non-ballast fertilizer. Externally, a colorless liquid. The physico-chemical properties of the fertilizer change depending on the ambient temperature. It is stored only in hermetic vessels, where it separates under pressure into liquid and gaseous phases.

When transporting, the containers are not completely filled. The substance is neutral to cast iron, iron and steel, but strongly corrosive to zinc, copper and their alloys.

- Ammonia solution in water, low vapor pressure, does not destroy ferrous metals. Nitrogen is found in the form of ammonia NH 3 and ammonium NH 4 OH. Free ammonia contains much more than ammonium. This contributes to the loss of nitrogen due to volatilization. Working with ammonia water is easier and safer than with anhydrous ammonia, but due to the low nitrogen content, its use is cost-effective only in farms located close to enterprises producing it.

Ammonia

contain from 30 to 50% nitrogen. Outwardly, it is a liquid of light yellow or yellow color. Ammonia is obtained by dissolving ammonium nitrate, ammonium and calcium nitrate, urea or ammonium nitrate and urea in aqueous ammonia.

Ammonia differs in the concentration of total nitrogen, in the ratio of its forms, and is diverse in physicochemical properties.

Ammonias cause corrosion of copper alloys. Ammonia with ammonium nitrate oxidize, in addition, and ferrous metals. Storage and transportation of ammonia is possible in containers made of aluminum, its alloys, stainless steel or in ordinary steel tanks with anti-corrosion coating with epoxy resins. It is possible to use containers made of polymeric materials.

(CAS)

- a mixture of aqueous solutions of urea and ammonium nitrate. CAS have a neutral or slightly alkaline reaction. Outwardly - transparent or yellowish liquids. By changing the ratio of the initial components, various grades of UAN are obtained.

Behavior in soil

All one-component nitrogen fertilizers are highly soluble in water.

Nitrate forms

move along with the soil solution and are bound in the soil only by the biological type of absorption. Biological absorption is active only in the warm season. From late autumn to early spring, nitrates move easily in the soil and can be washed out under the conditions of a leaching water regime, which is especially characteristic of light soils.

In the warm season, ascending moisture flows predominate in soils. And plants and microorganisms actively absorb nitrate nitrogen.

Ammonia and ammonium

forms in the soil are absorbed by the soil complex (SPC) and pass into the exchange-absorbed state. In this form, nitrogen mobility is lost, and it is not washed out. The exception is light soils with low absorption capacity.

Further nitrification processes contribute to the transformation of nitrogen into nitrate forms and its biological absorption by plants and soil microorganisms.

With urea

after its transformation under the influence of urobacteria into ammonium forms of nitrogen, the same thing happens.

Thus, nitrogen fertilizers initially or during the nitrification process accumulate in the soil in the nitrate form, which subsequently undergoes denitrification. These processes occur in almost all types of soils, and it is with them that the main losses of nitrogen are associated.

From an agronomic point of view, denitrification is a negative process. But from the ecological side, it plays a positive role, since it frees the soil from nitrates not used by plants and reduces their flow into wastewater and water bodies.

Application on various types of soil

The efficiency of applying nitrogen fertilizers depends on the soil and climatic conditions of the region. The greatest efficiency of nitrogen fertilizers is observed in areas of sufficient moisture.

Humus-poor soddy-podzolic soils, gray forest soils, podzolized, leached chernozems

. The effect of nitrogen fertilizers is steadily positive. Moreover, with an increase in the degree of leaching of chernozems, the effectiveness of nitrogen fertilizers also increases.

Sandy, sandy soils

non-chernozem zones are experiencing an acute shortage of nitrogen, so there is a high efficiency of nitrogen fertilizers. However, under the conditions of the leaching regime of the soil, significant losses of nitrogen are noted, and its introduction is carried out mainly in the spring.

Drained peat-bog soils

. The effect of nitrogen fertilizers is reduced, since phosphate and potash fertilizers are at a minimum. However, in the first years of development of peatlands in the central and northwestern regions of the non-chernozem zone, the effectiveness of nitrogen fertilizers also increases.

Podzolized and leached chernozems

the right-bank forest-steppe of Ukraine show greater efficiency in the use of nitrogen fertilizers than the left-bank.

Leached chernozems of the European part of Russia

. There is a lower efficiency of nitrogen fertilizers in the Volga region. In the Central Black Earth zone and in the North Caucasus, it is somewhat higher.

in the steppe zone

with an increase in the aridity of the climate, the effect of nitrogen fertilizers decreases or becomes very unstable. But under irrigation conditions, the effectiveness of nitrogen fertilizers increases and is even higher than that of phosphorus and potash fertilizers.

Typical chernozems

Moldavia are distinguished by large yield increases.

Ordinary and carbonate chernozems

Moldova are characterized by lower efficiency of single-component nitrogen fertilizers.

Ordinary chernozems

steppe regions of Ukraine. Nitrogen fertilizers show significant efficiency, but the effect is significantly weakened from west to east.

Ordinary and carbonate chernozems of the Kuban, foothills of the North Caucasus, northern Azov chernozems

have a significant positive effect of nitrogen fertilizers.

Carbonate chernozems of the Rostov region, ordinary chernozems of the Volga region

. Fertilizer efficiency is reduced.

chestnut soils

. At best conditions moistening, a good effect of fertilizers is noted. In dry conditions, the effect of nitrogen fertilizers is weak.

Impact on crops

Nitrogen fertilizers play a leading role in increasing the yield of various crops. This is due to the role of nitrogen as an important biological element that plays an exceptional role in plant life.

An adequate supply of nitrogen enhances the synthesis of organic nitrogenous substances. Plants form powerful leaves and stems, the intensity of the green color increases. Plants grow and bush well, the formation and development of fruiting organs improves. These processes contribute to increased yield and protein content.

However, it must be taken into account that a one-sided excess of nitrogen can delay the maturation of plants, promoting the development of a vegetative mass while reducing the development of grains, roots or tubers. In flax, cereals and some other crops, excess nitrogen causes lodging. (a photo) and deterioration in the quality of crop production.

So, in potato tubers, the starch content may decrease. In sugar beet roots, sugar content decreases and the content of non-protein nitrogen increases.

With an excess of nitrogen fertilizers, nitrates potentially dangerous to human and animal health accumulate in feed and vegetables.

Obtaining nitrogen fertilizers

The production of nitrogen fertilizers is based on the production of synthetic ammonia from molecular nitrogen and hydrogen.

Nitrogen is formed when air passes through a generator with burning coke.

Sources of hydrogen - natural gas, oil or coke oven gases.

From a mixture of nitrogen and hydrogen (ratio 1: 3) at high temperature and pressure and in the presence of a catalyst, ammonia is formed:

N 2 + 3H 2 → 2NH 2

Synthetic ammonia is used to produce ammonium nitrogen fertilizers and nitric acid, which is used to produce ammonium nitrate and nitrate fertilizers.

4.

Yagodin B.A., Zhukov Yu.P., Kobzarenko V.I. Agrochemistry / Edited by B.A. Yagodina.- M.: Kolos, 2002.- 584 p.: silt (Textbooks and study guides For university students).

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Nitrogen in organic fertilizers is contained in in large numbers. 0.5-1% nitrogen contains all types of manure. Bird droppings 1-2.5% nitrogen. The highest percentage of nitrogen is found in duck, chicken, and pigeon manure, but it is also the most toxic. The maximum amount of nitrogen contains vermicompost up to 3%.

You can also make natural organic nitrogen fertilizers with your own hands: compost heaps (especially on a peat basis) contain a certain amount of nitrogen (up to 1.5%), compost from household waste also contains up to 1.5% nitrogen. Green mass (lupine, sweet clover, vetch, clover) contain about 0.4-0.7% nitrogen, green foliage contains 1-1.2%, lake silt (1.7-2.5%).

For the "improvement" of compost, it is recommended to use a number of plants that contain substances that inhibit the development of putrefactive processes. These include leaf mustard, a variety of mints, nettles, comfrey (it is rich in soluble potassium), horseradish.

organic fertilizer with great content nitrogen can be prepared from mullein. To do this, put the mullein in the barrel, filling the barrel by one third, fill it with water and let it ferment for 1-2 weeks. Then dilute with water 3-4 times and water the plants. Pre-watering. You can do this. The introduction of any fertilizer acidifies the soil, so it is necessary to make ash, dolomite flour, lime.

But it is not recommended to carry out nitrogen fertilizers with ash at the same time. Because with this combination, nitrogen turns into ammonia and quickly evaporates.

So what is organic nitrogen for plant nutrition?

Natural nitrogen fertilizers and their nitrogen content.

• manure - up to 1% (horse - 0.3-0.8%, pork - 0.3-1.0%, mullein - 0.1-0.7%);
• biohumus aka vermicompost - up to 3%
• humus - up to 1%;
• droppings (bird, pigeon, duck) - up to 2.5%;
• compost with 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%.

Organic nitrogen fertilizers inhibit the accumulation of nitrates in the soil, but apply them with caution. The introduction of manure (compost) into the soil is accompanied by the release of nitrogen up to 2 g/kg within 3-4 months. Plants easily absorb it.

Some more statistics, one ton of semi-decomposed fertilizer contains 15 kg of ammonium nitrate, 12.5 kg of potassium chloride and the same amount of superphosphate.

Every year, up to 40 gr. bound nitrogen. In addition, the soil microflora that processes atmospheric nitrogen is able to enrich the soil with nitrogen in an amount of 50 to 100 grams per hundred square meters. Only special nitrogen-fixing plants can provide more bound nitrogen for the soil.

A natural source of organic nitrogen can be nitrogen-fixing plants used as cover crops. Certain plants, such as beans and clover, lupins, alfalfa, and many others, store nitrogen in their root nodules. These nodules release nitrogen into the soil gradually over the life of the plant, and when the plant dies, the remaining nitrogen increases the overall fertility of the soil. Such plants are called green manure and in general.

Weaving of peas or beans planted on your site in a year is able to accumulate 700 grams of nitrogen in the soil. Weaving clover - 130 grams. Lupine - 170 grams, and alfalfa - 280 grams.

Sowing these plants after harvesting and removing plant debris from the site will enrich the soil with nitrogen.

Milk whey as an organic source of nitrogen, phosphorus and potassium.

The most available nitrogen fertilizer for plants is whey. Due to the content of protein in it, which, in the process of watering plants with the addition of whey, enters the soil. And there, under the influence of soil microflora, nitrogen is released, which becomes available to plants. That is, nitrogen fertilization of plants is carried out in this way.

To carry out such feeding, it is necessary to dilute 1 liter of whey in 10 liters of water. And water the plants at the rate of 1 liter of serum diluted 10 times per plant.

If you first add 40 ml of pharmacy ammonia to 1 liter of serum. That ammonia reacts with lactic acid, which results in ammonium lactate.

Using a similar solution on a regular basis, we will not be able to affect the acidity of the soil, which is very good. Since if we would not add ammonia to whey. Then with the frequent use of whey for root feeding of plants, the acidity of the soil would inevitably increase.

In addition, whey itself contains a large amount of minerals. Each 100 grams of whey contains:

• 78 milligrams of phosphorus;
• 143 milligrams of potassium;
• 103 milligrams of calcium.

It also contains magnesium and sodium in small amounts.

comfrey officinalis

Natural nitrogen-containing fertilizers obtained by industrial processing.

Blood meal is an organic product made from dried blood and contains 13 percent total nitrogen. This is a very high percentage of nitrogen in the fertilizer. You can use blood meal as a nitrogen fertilizer by sprinkling it on the surface of the soil and pouring water over the top to help absorb the blood meal. You can also mix blood meal directly with water and use it as a liquid fertilizer.

Blood meal is a particularly good source of nitrogen for fertile soil lovers like lettuce and corn because it acts quickly.
Blood meal can be used as a component of compost or as an accelerator for the decomposition of other organic materials, as it catalyses decomposition processes.

Soy flour is a source of nitrogen nutrition for soil microorganisms. When soy flour is decomposed by soil microflora, then mineralized nitrogen will become available to plants. It can also be used as a compost ingredient along with fishmeal. Which, after mineralization, will become not only a source of nitrogen, but also a number of trace elements.

Nitrogen fertilizers Video:

Nitrogen is a very important element for healthy plant growth. It is this element that is responsible for the rich harvest and health of garden and indoor crops. Plants have a special need for nitrogen in the spring. During active growth, they need to get all the most valuable from the soil. To enrich the soil, you can use various industrial fertilizers, or you can prepare top dressing at home.

What plants need nitrogen

First of all, this trace element is necessary for vegetable crops. In order to grow a rich crop at home, you need to fertilize with nitrogen vegetables such as pumpkin, cabbage, zucchini, eggplant, peppers, potatoes. They need to be fed at planting and during active growth and flowering. Nitrogen is also required in large quantities by fruit and berry plants (raspberries, cherries and blackberries.) And ornamental crops (rose, peony, violet, etc.). These crops need a high nitrogen content in the soil. When using ammonium nitrate as a fertilizer for these plants, you need to use about 25 gr. fertilizers per 1 sq.m.

Slightly less nitrogen is required for cucumbers, tomatoes, beets, corn cobs, carrots and greens. Also, a large amount of this element is not required for annual flowers, currants, apples and gooseberries. The site for these plants must be fertilized with ammonium nitrate at the rate of 20 gr. per 1 sq.m.

An even smaller amount of nitrogen (15 grams per 1 sq.m.) is required for early potatoes, leafy vegetables, radishes and onions. The same amount of top dressing must be distributed in the places of planting bulbous ornamental plants and pears.

Only 8 gr. per 1 sq.m. nitrogen fertilizing is required for crops such as peas, spice crops, beans, azalea, heather, poppy.

How to determine nitrogen deficiency

Every summer resident should know the signs of a lack of nitrogen in the soil. Timely top dressing at home will avoid the death of plants and help to get a rich harvest. Common signs of nitrogen deficiency include slow growth and delayed flowering. Leaves and stems are weak.

• In a tomato, a lack of nitrogen manifests itself in the form of dropping the ovary, yellowing of the leaves and stunting.
• Leaves turn yellow and die off.
• Strawberries have a red stripe on the leaves along the edge.
• Roses don't bloom.
• In fruit trees, fruits are poorly tied, the ovary is small and often crumbles.

What fertilizer to choose

Today, the most common nitrogen fertilizers are ammonium nitrate and urea. These top dressings can be purchased at any garden store and can be successfully used at home. The key to using data chemical compositions exactly follow the recommended dosage for each crop.

You can also prepare nitrogen fertilizers at home. An excellent source of nitrogen is chicken or pigeon droppings.

In addition to nitrogen, these fertilizers contain other trace elements and minerals necessary for healthy plant growth.

Every summer resident can prepare bird droppings at home. Bird guano must be dried in a special oven and ground into powder. Bird droppings can also be mixed with hay or sawdust. After 2 months, you can fertilize the land with homemade useful compost.

Banana peels are also a good source of nitrogen and potassium. If you love bananas and eat these healthy fruits all winter, do not throw away the peel, but dry it. It is better to dry banana skins on a battery. After complete drying, the peel must be ground in a meat grinder, and in the spring, when digging up the garden, the chopped peel must be mixed with the soil. As the skin rots, nitrogen and potassium will be released into the soil, making your plants strong and healthy.

If you are making your own fertilizer using a compost pit, it is important that it contains peat. In the presence of peat, the nitrogen content in the compost increases.

Top dressing of indoor flowers

Like garden plants, indoor flowers also need nitrogen to good growth and timely flowering. Indoor flowers often need to be fed much more than plants in the garden.

This is due to the limited amount of soil in the pot, which is depleted over time.

For indoor flowers, pigeon droppings, saltpeter, banana peels, or urea can also be used as a nitrogen fertilizer. It is important not to overdo it and not oversaturate the earth with nitrogen, because in this case the plants may simply not bloom.

Feeding rules

AT agriculture there are generally accepted norms for applying nitrogen fertilizers to the soil. If you use dry top dressing, then 900 gr. powder per 100 sq.m.

For a one-time feeding of vegetables and fruits, it is enough to add 300 gr. to the soil. fertilizers per 100 sq.m.

When watering, fertilizers are diluted in an amount of 30 gr. for 10 liters of water. This solution should be enough for 10 sq.m.

For spraying, the powder is diluted in a proportion of 50 gr. for 10 liters of water. This solution should be enough for 200 sq.m.

It should be noted that these norms are only general rules, in order to calculate more accurate norms for applying fertilizer to the soil, many points must be taken into account, such as the composition of the soil, the plant's need for nitrogen, soil temperature, etc.

Harm or benefit

Many gardeners are sure that nitrogen fertilizing is extremely harmful. In their opinion, they accumulate in fruits in the form of nitrates, which everyone is afraid of. Experts partly agree with this opinion, but with the caveat that nitrates accumulate in fruits only if fertilizers are applied to the soil incorrectly.

In other words, if you overfeed your plants with nitrogen, the excess fertilizer may actually be in the fruits and tubers. Plants that do not need a lot of nitrogen tend to accumulate nitrates. Among such crops, early potatoes, beets, and leafy vegetables can be distinguished. In order to prevent fruit poisoning, it is important to strictly observe the dosage when feeding them.

When and how to apply fertilizer

Usually, fertilizers are applied when digging up the garden in the spring or directly when crops are planted. Remember that all organic fertilizers contain nitrogen, but it takes time for the plant to absorb it. For urgent top dressing, industrial nitrogen fertilizers are used, which are made from ammonia and nitric acid.

If you constantly grow garden and garden plants.

If you monitor the composition of the soil and regularly fertilize it with compost or bird droppings, you can not worry about a lack of nitrogen, because constant care of the soil allows you to enrich the soil.

With the regular use of organic fertilizers, the need for the use of industrial dressings disappears by itself.

Experienced summer residents know that if you carefully observe the seedlings, she herself will tell you about what vitamins she lacks. You just need to know how a particular plant reacts to a lack of useful elements. With timely diagnosis, the situation can be easily corrected with the help of natural and harmless dressings. In this case, you do not have to worry about the content of nitrates in your crop.

Everyone knows that in order for an organism to exist, the presence of oxygen, hydrogen, carbon and nitrogen is necessary. It is clear that nitrogen is one of the main elements in the life of both plants and humans and animals. For plants, the source of nitrogen is naturally the soil. Depending on the type of soil, its “wear and tear”, the amount of nitrogen in it also changes. Most often, nitrogen deficiency is felt by various crops growing on sandy and sandy loamy soils. It is these types of soils that always need additional enrichment with nitrogen fertilizers so that the plants feel normal on them.

Mineral nitrogen-containing fertilizer. © agrihol

It has been established that a significant proportion of nitrogen in the earth is concentrated in its layer, called humus, it contains more than 5% nitrogen. Naturally, the thicker the humus layer, the greater the amount of nitrogen, therefore, plants feel better on such soil.

Humus is a very stable substance, the process of its decomposition is slow, therefore, the release of mineral substances from this layer also occurs rather slowly. Only one percent of the five that is in the soil is a mineral compound that is soluble in water, and therefore available for consumption by plants.

Therefore, even in the presence of a thick layer of humus, additional feeding is necessary for plants, although at lower doses.

Why do plants need nitrogen?

This element, it turns out, is not found in every organic compound. For example, there is no nitrogen in sugars, fiber, oil and starch. There is nitrogen in amino acids and proteins. Nitrogen is an important component of nucleic acid, which is the main component of literally any cell responsible for protein synthesis and duplication of hereditary data (duplication is the formation of additional hereditary material identical to that already in the genome).

Even chlorophyll, which is known to help plants absorb solar energy, also has nitrogen in its composition. In addition, nitrogen is found in various components of the organic environment, for example, in alkaloids, lipoids, and similar substances.

The entire above-ground mass of plants has nitrogen, and most of this element is contained in the very first leaf blades. With the completion of flowering and the beginning of the formation of the ovary, this substance flows to the reproductive organs of plants and accumulates there, forming proteins.

During the period of seed ripening, nitrogen is taken from the vegetative organs in the maximum amount, and they are greatly depleted. If there is a lot of nitrogen in the soil and the plant consumes it in large quantities, then this element will be distributed to almost all organs of the plant, which will lead to a rapid growth of the above-ground mass, delays in the ripening of berries and fruits, and a decrease in the total plant yield.

Only a balanced concentration of nitrogen in the soil can guarantee high yields and sufficient product quality.

Those plants that consume nitrogen in abundance, and not in excess, can fully develop, form standard leaf blades of a typical, often green, color, otherwise they will wither and form mediocre yields.

Corn treated with nitrogen fertilizers (background) and not treated. © Nora Nolden

Varieties of fertilizers containing nitrogen

Nitrogen fertilizers are substances that contain nitrogen compounds. In total there are several main groups of nitrogen fertilizers. These are nitrate fertilizers (calcium and sodium nitrate), ammonium fertilizers (ammonium chloride and ammonium sulfate), ammonium nitrate fertilizers (ammonium nitrate), amide fertilizers (urea), and liquid nitrogen fertilizers (ammonium water or anhydrous ammonium).

Nitrogen fertilizers, nitrate group

Let's start with calcium nitrate, is its chemical formula Ca(NO₃)₂. Externally, calcium nitrate is a snow-white granules, in which nitrogen contains up to 18%. This fertilizer is suitable for soils with high acidity. With the systematic and annual introduction of calcium nitrate into the soil with high acidity, an improvement in its properties is observed. Calcium nitrate is highly soluble in water, so you need to store the fertilizer in bags that do not let water through.

When making calcium nitrate, you need to remember that its mixing with phosphate fertilizers is unacceptable.

The next fertilizer is sodium nitrate, its chemical formula is NaNO₃. This fertilizer is crystalline, it contains a little less - up to 17% nitrogen. Sodium nitrate is highly soluble in water and is perfectly absorbed by plant roots. This fertilizer is universal and suitable for various crops. This fertilizer cannot be applied in the autumn period: the nitrogen contained in it will be actively washed off into groundwater.

Given the excellent solubility in water and hygroscopicity, this fertilizer should be stored in dry places.

Ammonium fertilizers

The next group is ammonium fertilizers. First in this group is ammonium sulfate, its chemical formula is (NH 4) 2 SO 4 . Externally, this fertilizer is a snow-white powder, which contains a little more than 20% nitrogen.

Ammonium sulfate can be used both as a basic nitrogen fertilizer and as an additional top dressing. The introduction of this fertilizer can be carried out in the autumn: nitrogen from it is fixed in the soil, without being washed off into groundwater.

With the annual and systematic application of ammonium sulfate to the soil, soil acidification may occur, for which this fertilizer must be mixed with lime or chalk in a ratio of one to two.

Ammonium sulfate is not hygroscopic, so storage is usually not a problem. The main thing to remember is that this fertilizer cannot be applied in combination with any alkaline top dressing, because there is a risk of suppressing nitrogen activity.

Ammonium chloride, is its chemical formula NH₄Cl. This fertilizer contains about 26% nitrogen. Externally, ammonium chloride is a yellow-white powder. When ammonium chloride is applied, it is not washed out of the soil, this fertilizer does not cake during storage, and even after many years of storage it does not require grinding. Nitrogen released from ammonium chloride into the soil is perfectly absorbed by plants.

The main disadvantage of this fertilizer is the chlorine contained in its composition. So, when 10 kg of nitrogen is added to the soil, in terms of the active substance, about twice as much chlorine gets into the soil, and it is considered poisonous for most plants. Taking this into account, the introduction of ammonium chloride should be carried out exclusively in the autumn period in order to deactivate the chlorine component, but along with this, up to 2% of nitrogen is lost.

Ammonium nitrate fertilizers

The next category is ammonium nitrate fertilizers, the leader in this group is ammonium nitrate. Chemical formula ammonium nitrate looks like this - NH₄NO₃. This fertilizer is in the form of a whitish granular powder. The fertilizer contains about 36% nitrogen. Ammonium nitrate can be used as a basic fertilizer or as an additional top dressing.

This fertilizer is categorized as a non-ballast substance, so its main use falls on regions with a deficit of water moisture. It is noteworthy that on soils with excess moisture, the effectiveness of the use of this fertilizer is reduced to a minimum, since the nitrogen contained in the fertilizer is almost completely washed off into groundwater.

Ammonium nitrate, due to its increased hygroscopicity, does not tolerate storage in damp rooms, where it quickly hardens and cakes. Of course, this does not mean that the fertilizer becomes unusable, just before applying it to the soil, it will be necessary to grind the saltpeter, which is sometimes quite difficult.

In the event that your plans include creating a mixture of ammonium nitrate and phosphate fertilizer, for example, then you should initially mix superphosphate with any neutralizing fertilizer, for example, dolomite flour, chalk or lime, and the next step is to mix it with ammonium nitrate.

Do not forget that the systematic and annual introduction of ammonium nitrate into the soil leads to an increase in its acidity. It is noteworthy that the level of soil acidity increases most actively with time, and at the initial stages of its introduction, the change in acidity is imperceptible.

In order to prevent acidification of the soil, ammonium nitrate must be applied together with chalk, dolomite flour and lime in a ratio of 1 to 2.

Interestingly, at present, pure ammonium nitrate is practically not sold, it is sold in the form of various kinds of mixtures. It is very popular and has good feedback when using a mixture consisting of 60% ammonium nitrate and 40% of various neutralizing components. In this ratio, the mixture contains approximately 19-21% nitrogen.

Nitrogen fertilizer granules - urea. © thechemco

Group - amide fertilizers

Urea, - its chemical formula is CH 4 N 2 O. Urea is called differently - carbamide, this fertilizer is considered one of the most effective. Urea contains about 47% nitrogen, sometimes - 1% less. Outwardly, these are snow-white granules. This fertilizer is characterized by an increased ability to acidify the soil, so it can only be applied with neutralizing substances - dolomite flour, chalk, lime. Urea is rarely used as the main fertilizer, it is usually used as an additional foliar top dressing. This is an excellent foliar fertilizer also because it does not burn leaf blades, but is well absorbed by plants.

In total, two brands of urea are known, which are called - A and B. The brand under the name A does not belong to the category of highly effective and is extremely rarely used in crop production. Typically grade A urea is used for animal feed additives, eg goats, cows, horses. The brand of urea with the name B is urea processed with additives, used specifically as fertilizers.

Liquid nitrogen fertilizers

Ammonia hydrate, or ammonium hydroxide (ammonia water or liquid ammonia). The chemical formula of ammonium hydroxide is NH 4 OH. Essentially, ammonia water is ammonia dissolved in water. In total, there are two types of liquid ammonia, the first contains nitrogen at least 19% and no more than 26%, and the second can contain from 15% nitrogen to 21%. Usually, ammonia water is applied with special equipment capable of planting this fertilizer into the soil to a depth of about 14-16 cm.

The advantages of liquid fertilizers are their extremely low price, fast digestibility by plants, long period of action and even distribution of fertilizers in the soil. There are also disadvantages - this is a rather complicated transportation and storage, the possibility of severe burns on the leaves when fertilizer gets on their surface and the need for special equipment designed for applying liquid fertilizers.

Organic nitrogen fertilizers

As you know, nitrogen is present in organic compounds, but its amount there is small. So, for example, in the litter of a large cattle nitrogen not more than 2.6%. In bird droppings, which is quite toxic, it is up to 2.7%. Nitrogen is also present in the compost, but the amount of nitrogen there, depending on the "ingredients" of the compost, is very different. Most nitrogen in compost prepared from lake silt, leaf litter, green mass of weeds and lowland peat. Given the instability of the nitrogen content in organic fertilizers, its use as the main fertilizer is not desirable and threatens with nutritional deficiency and nitrogen starvation for plants. In addition, such fertilizers, although slowly, but still acidify the soil.

Crops for which nitrogen is especially important

In general, each crop needs nitrogen, however, the application rates for certain crops vary. Given this, all plants can be grouped into categories according to the need for nitrogen.

To the first category you can include plants that need to be fed with nitrogen before planting them in the ground to activate growth and development. For such crops, about 26-28 g of nitrogen are needed per square meter in terms of ammonium nitrate and per square meter of area. This category includes, from vegetable crops: potatoes, cabbage, bell peppers, eggplant, zucchini, pumpkin and rhubarb; from berries and fruits: plum, cherry, raspberry, blackberry and strawberry; from flowers: lilac, rose, dahlia, peony, violet, phlox, balsam, carnation, nasturtium and zinnia.

Second group These are crops that need less nitrogen. Usually only 18-19 g of nitrogen in terms of ammonium nitrate and per square meter of area is sufficient. From vegetable crops, this can include: tomatoes, parsley, cucumber, carrots, corn, beets and garlic; from fruits and berries: apple, currant, gooseberry; from flowers: all annuals and delphiniums.

Third category- these are plants that need nitrogen in moderation, not more than 10-12 g per square meter in terms of ammonium nitrate. Vegetables in this category include: potatoes early term ripening, salad crops, radishes and onions; from fruit - it is a pear; from flowers: bulbous, primrose, adonis, saxifrage and daisy.

Final category requires the introduction of a minimum amount of nitrogen per square meter, not more than 5-6 g in terms of ammonium nitrate. From vegetable crops, spicy herbs and legumes can be included here; from flowers - poppy, azalea, young, heather, stonecrop, erica, purslane, rhododendrons and cosmea.

Rules for the use of nitrogen fertilizers

Remember that only optimal doses of nitrogen fertilizers can positively affect the development and growth of various crops, and you need to be able to calculate top dressing based on the percentage of nitrogen in a particular fertilizer, and also apply them according to soil type, season and plant species.

So, for example, when nitrogen is introduced into the soil in autumn, there is a risk of it being washed off into groundwater. Therefore, the most suitable period for applying fertilizers containing nitrogen is spring.

If you plan to fertilize soils with high acidity, then be sure to mix nitrogen with various components that neutralize the acidifying effect - chalk, lime, dolomite flour. Thus, fertilizers will be absorbed better, and the soil will not acidify.

For residents of the steppe zone and forest-steppe, where the soils are predominantly dry, it is very important to apply nitrogen fertilizers periodically, without abrupt breaks, which can affect plants in the form of delays in growth, development, and a decrease in yield.

The introduction of nitrogen fertilizers into the chernozem soil is best done 11-12 days after the snow melts. It is desirable to carry out the first top dressing using urea, and when the plants enter the active phase of the growing season, add ammonium nitrate.

The consequences of a lack of nitrogen

We have already partially mentioned this, but nitrogen deficiency is not only manifested in growth inhibition. In addition, quite often the leaf blades of plants begin to acquire an atypical color, they turn yellow, and this is the first signal to fertilize. With a strong nitrogen deficiency, in addition to yellowing of the leaf blades, their tips slowly begin to dry out.

Signs of nitrogen deficiency on corn leaves. © Chad Lee

Can nitrogen fertilizers be harmful?

Yes, maybe, in case of an overabundance of them. Usually, with an excess of nitrogen, the above-ground mass of plants begins to develop too actively, the shoots thicken, the leaf blades increase, and the internodes become larger. The green mass acquires atypical splendor and softness, and flowering is either weak and short, or does not occur at all, therefore, the ovary does not form and fruits and berries do not form.

If there is a lot of nitrogen, then something like burns appears on the leaf blades, in the future such leaves die off and fall off ahead of time. The death of foliage sometimes leads to partial death of the root system, which is why the introduction of nitrogen must be strictly normalized.

Results. So, we realized that all plants need nitrogen fertilizers, but it is necessary to correctly determine their dosages and apply them in accordance with the recommended terms, relying, among other things, on the properties of the fertilizers themselves.

Without nitrogen, the existence of protein forms of life, which include, among other things, plants, is impossible. This element serves as a structural unit for building amino acids and proteins. Plants take it out of the soil in large quantities. The material below tells about how to replenish nitrogen reserves and what fertilizers belong to the nitrogen group. We will analyze what types of nitrogen fertilizers to use in the garden in autumn and spring as top dressing.

Natural sources of nitrogen for plants

In the natural environment, nitrogen is not lost anywhere. It circulates in a circle, and no matter how wildly trees and grasses grow in a field or in a forest, they have enough nitrogen. The cycle of this element in nature is carried out according to the following scheme:

• plants take nitrogen out of the soil and use it to build their protein molecules and amino acids;
• animals eat plants and transfer nitrogen from their cells to their own to build their own proteins and amino acids;
• animals and plants die, are decomposed by soil microorganisms, which convert their remains into humus, then mineralize and return nitrogen to the soil.

In fact, the nitrogen cycle is more complicated, but even such a simplified version explains why the “wild” lands are not depleted. Moreover, the longer a natural community exists, the richer the soil becomes in nitrogen and other elements.

Things are quite different on “cultural” agricultural lands. Traditional agricultural practices involve the complete harvesting of crop residues, thorough weeding and the removal of green mass from the field or garden. The earth is plowed or deeply dug up with the turnover of the layer, as a result of which soil microorganisms die. The nitrogen cycle stops. Planted crops take nutrition from the soil, but do not return anything to it.

Important! The use of nitrogen fertilizers is mandatory in areas where traditional agricultural practices are used. There are no natural sources of nitrogen on such lands, they are very quickly depleted, and the yield decreases. Fertilization, in this case, is the only way to replenish mineral reserves.

General classification of nitrogen fertilizers

All nitrogen fertilizers can be divided into two large groups:

Nitrogen fertilizer group	general description	Examples
	They are chemically obtained salts. They contain a lot of nitrogen in various forms - nitrate, ammonium, amide.	Urea, ammonium nitrate (), ammonium sulfate, etc.
organic	Waste products of animals or the remains of dead plants. They are complex complexes of organic acids, metabolites, vitamins, proteins, carbohydrates, mucus, mineral salts.	Manure of varying degrees of decomposition, compost, biohumus, etc.

Thus, mineral nitrogen fertilizers purposefully supply plants with nitrogen. Organic give not only nitrogen, but also many biologically active compounds.

Forms of nitrogen: behavior in soil and uptake by plants

Introduced in the form of salts, nitrogen undergoes the same transformation. Depending on the form in which it is initially located, mineral fertilizer behaves differently in the soil:

Chemical analysis of soils after the application of mineral nitrogen fertilizers shows that nitrate fertilizers are most fully absorbed by plants. Ammonium nitrogen is partly fixed irreversibly. Only part of it passes into the exchange form and is used by plants.

Mineral fertilizers with nitrate form of nitrogen

To nitrate mineral fertilizers include the following salts:

• Calcium nitrate. Easily soluble compound suitable for quick root dressings in the form aqueous solution on acidic soils. To prepare the solution, 20-30 g of saltpeter is taken per 10 liters of water. Plants are watered in the initial phase of vegetation with an interval of 15 days. Learn more → .
• Sodium (soda) nitrate. Popular fertilizer for the spring basic application to the soil. Alkalizes acidic soil. It is applied during spring tillage at the rate of 40 g per 1 m 2 . Learn more → .

Nitrate fertilizers are widely used by agricultural producers in central Russia, where acidic podzols predominate. In the Chernozem region, these salts are ineffective.

Mineral fertilizers with ammonium form of nitrogen

This group of nitrogen fertilizers includes sulfates and ammonium chlorides:

• Ammonium sulfate. Easily soluble salt, suitable for the main application and liquid dressings. Depending on the crop, 20-40 g per 1 m 2 is applied to the soil. Liquid top dressing is prepared at the rate of 10-20 g per 10 liters of water. Learn more → .
• Ammonium sodium sulfate. In agriculture, it is used for fertigation of beet and cabbage crops. The solution is prepared at the rate of 100 g per 100 liters of water.
• ammonium chloride. Contains up to 67% chlorine, therefore it is not used for nitrogen fertilizing of chlorophobic plants (pumpkin, potatoes, grapes, cabbage, etc.). To reduce toxicity, it is used only in the autumn main application to the soil.

Ammonium fertilizers have a longer effect than nitrate ones, but are less absorbed and often cause an imbalance of nutrients. The absorption of calcium, potassium and manganese by plants against the background of the use of this group of fertilizers is reduced.

Mineral fertilizers with amide form of nitrogen

This group includes only one popular fertilizer in the horticultural environment - carbamide, otherwise referred to as urea. Urea is more often used for spraying plants, since the amide form in the soil must undergo long-term transformations, during which a lot of nitrogen is lost.

Concentration and dosage of urea for spraying (click to expand)

A solution of urea for spraying is prepared in different concentrations:

• for apple trees and all vegetable crops - 0.3% (30 g per 10 liters of water);
• for pears - 0.1-0.3% (for 10 liters - 10-30 g);
• for stone fruits and berries - 0.6% (per 10 l - 60 g).

Carbamide can be introduced into the soil strictly under the condition of abundant irrigation, 0.5 kg per 1 weave. Only in dissolved form, this fertilizer is quickly ammonified. If there is not enough moisture, nitrogen from urea will begin to volatilize in the form of ammonia.

Organic fertilizers as a source of nitrogen

The use of mineral fertilizers is by no means an ideal way to replenish the nitrogen carried out by plants. They give a strong momentary effect, but at the same time they kill the soil.

“Mineral fertilizers help us solve our problems. We go to large volumes of production with minimal costs and give people food. But after all, this is work according to the principle “we will take what is ours today, and then, at least the grass will not grow.” We will leave a barren desert behind us.”

J. Granowski, Polish farmer

Organic fertilizers are a good alternative to salts. They provide food for microorganisms and restore the normal structure of the soil and its biochemical balance.

All types of organic fertilizers can be considered as a source of nitrogen:

• animal manure - about 0.6% nitrogen; ( see →)
• bird droppings - about 1.6% nitrogen; ( see →)
• humus - about 1% nitrogen; ( see →)

Of course, they are not without flaws. For example, with manure or improperly prepared compost, pathogenic flora, helminth eggs and weed seeds can be brought to the site.

Another minus is that organic matter seriously loses to mineral fertilizers in terms of the percentage of nitrogen. To make up for its losses of organic fertilizers, a lot is needed, and this can “hit the pocket” of a summer resident.

And yet, for farmers who care about the long term and want to preserve the fertility of their land, it is better to use this particular type of fertilizer. Physiologically, they are the closest to nature, and their shortcomings are easily eliminated with proper use.

The use of nitrogen fertilizers on soils of different types

The effectiveness of nitrogen fertilizers largely depends on soil conditions. The leaching regime, the amount of precipitation falling in the region, and the level of acidity also have their influence:

soil type	Efficiency of nitrogen fertilizers	Additional terms
Podzolic and gray forest	+++	They contain little humus, so the introduction of organic matter is preferable. Acidity control required.
Non-chernozem sandy loam	+++	Nitrogen is easily washed out, so high doses of fertilizers are required. Preferred organics in order to increase the supply of humus.
leached chernozems	++
chestnut soils	++	Good irrigation is required to improve efficiency.
Ordinary and carbonate chernozems	+	Efficiency varies by region. Acidity control required.

In the north-west of Russia, where drained peatlands are actively developed, the efficiency of nitrogen fertilizers is high, but may decrease over time. Here it is better to use complexes containing, in addition to nitrogen, potassium and phosphorus.

Terms of application of nitrogen fertilizers

Nitrogen is urgently needed by plants at the beginning of the growing season, when there is a rapid increase in the vegetative mass and roots. From the second half of summer, an excess of this element negatively affects the yield and quality of fruits. Therefore, the terms of application of fertilizers containing high nitrogen are limited.

Liquid fertilizing with nitrogen fertilizers is carried out from May to mid-July. In greenhouses, the fertilizing season begins earlier - from March-April.

The main application of nitrate fertilizers is advisable only in the spring. They are not used in autumn, since nitrogen will easily leave with precipitation and spring meltwater. Ammonium fertilizers, due to their low mobility, can be incorporated into the soil in the fall, after harvesting.

Organic nitrogen fertilizers are applied from spring to mid-summer. If not rotted manure is used, then it can be laid in the soil when preparing the site for winter.