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Ammonium nitrate: properties, composition, fertilizer application

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Ammonium nitrate: properties, composition, fertilizer application
Ammonium nitrate: properties, composition, fertilizer application

Ammonium nitrate is chosen as the main source of nitrogen for plants during the period of active growth by many gardeners and agronomists. This is due to its versatility: it can be used equally successfully for feeding almost all crops, and it is also suitable for most types of soil.

A feature of the ammonium nitrate formula is the presence of nitrogen in it in two forms - nitrate and amide - NH4NO3. Due to this, the period of assimilation of it from the soil by plants is somewhat extended. Nitrogen in the composition of the nitrate ion begins to be absorbed immediately after application under the root, but amide not earlier than a week after top dressing.

ammonium nitrate formula

Types of drugs

Usually this fertilizer is produced with the addition of various elements. This is due to the geographical extent of the use of ammonium nitrate, as well as the need to adapt to the needs of farmers in different climatic zones.

  • Grade A. Used in various industries. Must contain at least 98% ammonium nitrate and not more than 0.3% water. The content of conditioning (stabilizing)additives, which are usually used as magnesium and calcium nitrates, should be 0.2-0.5% for calcium oxide and 0.5-1.2% for Р2О 5.
  • Grade B. Used exclusively for agricultural purposes. The nitrogen content in it should be at least 34%, and moisture, as well as for brand A, not more than 0.3%. Ammonium nitrate of this particular brand is sold in garden stores and has a convenient packaging. It is divided into the highest, first and second grades, the main difference of which is the strength and size of the drug granules.
  • Porous modified. This type of s altpeter is used as a raw material for the production of industrial explosives, which, in turn, are used in mining, oil, gas, construction and other industries.

Production of ammonium nitrate

The technological process of obtaining this fertilizer is quite complicated and includes several stages:

1. First, a solution of magnesium nitrate (magnesium additive) is obtained, which improves the physico-chemical properties of s altpeter:

Mg2+ + 2HNO3 → Mg(NO3) 2 + H2O + Q.

This process takes 4 hours at about 80°C and atmospheric pressure.

2. Nitric acid is neutralized with ammonia, resulting in the formation of ammonium nitrate in the form of a solution. This process is carried out at atmospheric pressure and a temperature of 148-165 ° С.

NH3 + HNO3 ↔ NH4NO3+ Q.

3. Nitrate solutionammonium enters the after-neutralizer, where excess nitric acid is neutralized by gaseous ammonia. To maintain an alkaline environment, a magnesium additive is added to the solution and sent to the stage of evaporation and granulation.

Storage and security

Due to the fact that the nitrogen contained in ammonium nitrate has the ability to evaporate, the opened package of fertilizer should be used within a month. S altpeter sealed in a moisture-proof container is stored for no more than six months. At the same time, the room should be cool and there should be no direct sunlight.

This fertilizer is a fire and explosion hazard, its self-ignition temperature is 350 °C. But already at a temperature of 210 ° C, it decomposes with the formation of nitrogen oxides and water vapor. And when nitrogen oxides interact with nitrate, flammable oxygen and ammonia are released. When s altpeter is mixed with metal powders, sawdust or straw, sugar and some other organic substances, a large amount of heat is released, which can provoke the above process.

mulching plants

It is also recommended to protect the granules of the drug from mechanical influences, such as shock and friction, which can provoke an increase in their temperature.

Accumulation of nitrates in vegetables

Ammonium nitrate is a nitrate fertilizer. Thanks to the educational work of the media, many people have concluded for themselves that even a tiny amount of nitrates in foods has a detrimental effect.on the human body. And the reason for their accumulation in fruits is exclusively mineral fertilizers, in particular, s altpeter.

However, this point of view is wrong. Firstly, nitrates not only enter living organisms with food, but are also formed in them during natural biochemical reactions. For comparison, the maximum allowable amount of nitrates that can be obtained from food without harm to he alth is 325 mg per day. And in the human body they are formed over the same day at least 100 mg.

Secondly, it is not the nitrates themselves that are harmful, but the nitrites formed during their restoration. Symptoms of poisoning with them are nausea, weakness, diarrhea, shortness of breath. To alleviate the condition, it is necessary to wash the stomach, take absorbents such as activated charcoal, fresh air.

Thirdly, the accumulation of nitrates in vegetables and fruits can also be provoked by shock doses of organic fertilizers, such as manure, bird droppings, and even herbal infusions. It is important to feed plants at certain periods of their growth and in the required quantities. As a rule, nitrogen fertilizers are stopped 2-3 weeks before harvest.

fruits and vegetables

It is also worth noting that not all plants accumulate nitrates with the same force. The champions in their content are greens: dill, lettuce, parsley, and beets. But watermelons and melons, with proper agricultural technology, store nitrates even less than white cabbage.


The popularity of using ammonium nitrate for plant fertilizer is due to a number of undeniablePros:

  • affordable drug cost;
  • possibility of application both in dry and dissolved form;
  • suitable for root and foliar applications;
  • works well in cold soils in early spring;
  • good diffusion ability.

The last property of ammonium nitrate allows the granules to dissolve perfectly in moist soil and penetrate quite deeply into it, delivering nutrition to plants with a powerful root system. However, it is also included in the list of cons.

garden after rain


Due to its high solubility in too wet soils and in areas with high groundwater levels, this fertilizer is not practical, as it will immediately wash out. Also, top dressing carried out before heavy rain will be ineffective.

Also, a significant disadvantage of the drug is called its physiological acidity. Regular use on soils with a low content of bases (podzolic soils, subtropical red soils) provokes an increase in their acidity, and, consequently, a decrease in yield. To neutralize this effect, it is recommended to add dolomite or lime to the soil.

Feeding tomatoes

The introduction of ammonium nitrate when growing tomatoes can be done at the seedling stage. It promotes the growth of strong seedlings. Fertilizing tomato seedlings with nitrogen preparations is carried out three times:

  • after picking: 10 g of ammonium nitrate is mixed with 10 g of potassium s alt (KCl) and 40 g of superphosphate, and then the resultingmixture in a bucket of water;
  • 2 weeks after the first feeding: 15 g of s altpeter, 20 g of KCl and 70 g of superphosphate are dissolved in 10 liters of warm water;
  • a week before planting in the ground: for 10 g of ammonium nitrate, take 40 g of superphosphate and 60 g of potassium s alt, dissolve the mixture in a bucket of water.
tomato seedlings

To prevent young plants from getting chemical burns, it is important to water them with plain water before feeding, and then with a solution of the drug. In this case, it is necessary to avoid getting it on the stems and leaves of seedlings. If drops of fertilizer fall on young greenery, then immediately rinse it with clean water.

The next top dressing is carried out already in the open field and its period depends on the quality of the preparation of the planting holes. With the right agricultural technology, it is performed after the seedlings adapt to the new place and its active growth begins. With the advent of flowers and ovaries, feeding with ammonium nitrate should be stopped.

Feeding cucumbers

This crop is fed with ammonium nitrate as part of a mixture with other mineral fertilizers that provide potassium and phosphorus. Do it at least twice a season:

  1. After the appearance of two pairs of true leaves: 10 g of s altpeter, KCl and superphosphate should be taken for 10 liters of water.
  2. With the beginning of flowering: 30 g of ammonium nitrate, 20 g of potassium s alt and 40 g of superphosphate are dissolved in a bucket of water.
growing cucumbers

Since cucumbers develop quite quickly, this is enough to get a goodharvest. Overfed with nitrogen, they will be reluctant to form ovaries, and this will affect the decrease in the number of fruits.

Feeding potatoes

Feature of this crop are underdeveloped roots and very large tubers that accumulate various nutrients that enter and form in the plant. It is easy to imagine that when growing potatoes in the same place from year to year, the soil loses colossal amounts of trace elements. If they are not replenished, then over time the tubers become smaller due to lack of nutrition.

When preparing the field for planting potatoes, it is necessary to scatter ammonium nitrate granules at the rate of 30 g per 1 square meter immediately after the snow melts. Dissolving in rainwater, it will seep to the desired depth, and subsequent harrowing of the site contributes to its uniform distribution. It is also recommended to combine s altpeter with superphosphate, which is consumed in the amount of 15 g per 1 m32.

Root feeding of potatoes with ammonium nitrate is carried out before hilling and after abundant watering. The working solution is prepared at the rate of 20 g of s altpeter and 40 g of superphosphate per 10 liters of water.

potato tubers

The effect of the drug on the body

Ammonium nitrate can enter the body through the respiratory system, the gastrointestinal tract, getting on the skin and in the eyes. S altpeter dust when inhaled has an irritating effect on the upper respiratory tract, mucous membranes of the eyes, skin (especially if there are cracks and wounds). Affected areas should be washed with plenty of running water inwithin 15 minutes. Rinse the nose and mouth thoroughly and provide the victim with access to fresh air.

When ingested, s altpeter causes dizziness, nausea and vomiting. Activated charcoal, plenty of fluids and a saline laxative are used as first aid.

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