Urea is a simple single-element fertilizer that supplies the soil with the main element - nitrogen in ammonia form (NH4 +). Urea is the richest source of nitrogen among conventional dry fertilizers. Anhydrous ammonia (NH3), containing 82% nitrogen, is a liquid under pressure (liquefied gas), which when released turns into gas.

Urea fertilizer has the formula CO (NH2) 2 and is sold in crystalline organic form. This fertilizer dissolves well in water and quickly seeps into the soil. Urea contains ROS (nitrogen-phosphorus-potassium) and is considered the most preferred dry nitrogen fertilizer in the world because of benefits such as high nutrient levels, ease of handling and reasonable price per unit of nitrogen.

The use of urea with a lack of nitrogen in plants

With a lack of nitrogen, plants die. They turn pale, lose their green pigment, grow less than expected growth and yield a meager harvest. In this regard, the enrichment of the soil with this element is a priority for absolutely any green space.

The percentage of nitrogen in urea is 46.6% and this is the main element that makes plants stronger, more nutritious and directly affects their growth.

Previously, the main form of urea delivery was nature, but with the invention of granules, the delivery of the most important nutrient has become more efficient in conditions of sufficient humidity.

This fertilizer is made from carbon dioxide and synthetic anhydrous ammonia (NH) and is sold in the form of granules, crystals, flakes and liquids. More than 90 percent of the 140 million tons of urea produced annually is used as fertilizer for agricultural purposes.

Urea (urea) can be dissolved in water and used as soil, deciduous irrigation or otherwise distributed with irrigation water. When urea fertilizer is applied to the soil, it combines with water (hydrolysis) to form ammonium carbonate [(NH4) 2CO3] through the catalytic action of urease. Moisturizing enzyme is present in the soil as a result of the decomposition of organic matter by microorganisms.

Urea fertilizer: instructions for use in the garden

Ammonium carbonate is unstable. It decomposes into gaseous ammonia, carbon dioxide and water. When introduced into the soil, ammonia is converted to ammonium with an additional hydrogen ion coming from the soil solution or from soil particles. Then positively charged ammonium ions are fixed in negatively charged particles of the soil, where they remain until they are absorbed by the plants through the roots or used by bacteria as an energy source and are not converted into nitrate during nitrification.

Here are some tips for using urea fertilizer in your garden and in the garden:

  1. The use of urea by dissolving in the soil. As a rule, urea should not be applied to the surface of the soil or plants without ensuring its immediate absorption. Since when anhydrous ammonia, a product of urea hydrolysis, is applied to the soil surface, it will immediately turn into a gas and dissolve. This process is called ammonia volatilization. Significant nitrogen loss from urea can be reduced or eliminated by tilling the soil, such as plowing, or by irrigation. Being highly soluble in water, urea fertilizer in the soil behaves in the same way as other nitrogen fertilizers. This means that once in the soil, nutrients from the fertilizer will remain in it.
  2. Apply separately or mix with approved fertilizers. Urea fertilizer can be applied separately or mixed with some other selected fertilizer materials. However, some mixtures should be applied immediately after mixing. Moreover, it cannot be mixed with some fertilizers, because a reaction will occur that will make some of the nutrients useless. Mixing basic materials with urea will result in nitrogen loss in the form of ammonia.

Fertilizers that can be mixed with urea:

  • calcium cyanamide;
  • potassium sulfate;
  • potassium magnesium sulfate.

Fertilizers that can be mixed with urea, but not stored for more than 2-3 days:

  • Chilean nitrate;
  • ammonia sulfate;
  • nitrogen magnesia;
  • diammonium phosphate;
  • main slag;
  • potassium solution.

Fertilizers that cannot be mixed with urea:

  • calcium nitrate;
  • calcium ammonium nitrate;
  • ammonium nitrate;
  • potassium nitrate;
  • superphosphate.

In fact, here we are not talking about individual, but about the so-called compound fertilizers (mixtures). Compound fertilizer is more nutritious in its content and provides simplicity and economy in practice, since it contains many nutrients. But in the event that the percentage of nutrients in the mixture is not suitable for the needs of the specific soil necessary for growing plants, their use cannot provide the expected benefits. And if it is required to enrich the soil for a single crop once, then such mixtures cannot be used.

Urea application time

Since nitrogenous fertilizers are very active in the soil, they can easily go into the gas or wash off with excess rain and water for irrigation.It is necessary to prevent such a loss and provide the soil with a timely supply of nitrogen precisely when the plant is most in need of nutrients. On the other hand, nitrogen should be abandoned in dry years. In a well-treated fertile soil with a normal annual rain cycle, it is also necessary to use a sufficient amount of urea.

When nitrogen deficiency is observed on the fruit tree, urea in a concentration of 0.5-1.0% should be applied by spraying before flowering and in autumn. To satisfy the nitrogen deficiency in fruit trees, nitrogenous fertilizers are dispersed along the crown of the tree (provided that the area is 0.5 m around the trunk), and then they interfere with the soil using a dredge or hoe.

For pollination of vineyards, urea should be used during tillage in February or March, this should be the first fertilizer used in the season.

For vegetables, top dressing with nitrogen is done 1 or 2 times during the growing season. Half of the nitrogenous fertilizer, preferably in the form of ammonium sulfate, should be interfered with in the soil within a radius of 5-10 cm near the trunk 15 days after planting. The second half is given after fixing the fruits.

When farming in the garden (for melon, watermelon), the first half of nitrogen fertilizer should be applied near embankments for sowing and germination. The second half of nitrogenous fertilizer should be scattered around the holes, or near the beds and treated with a hoe.

Urea application methods

For convenient use of fertilizers, the method and time of their addition to the soil and to the object are extremely important. The right choice of method increases the degree of fertilizer efficiency.

Five methods are used for fertilizing:

  1. Deep fertilizer.
  2. Ordinary application (beds).
  3. Use a sprinkler on the top and sides.
  4. Spraying onto leaves.
  5. The use of irrigation with water for irrigation.

Let's consider each method separately.

Deep fertilizer

This method involves irrigation at an early stage. It is used both immediately after germination of the sprout, and as a spread of granules on the soil surface manually or using a machine immediately before plowing and sowing. This method provides the penetration and assimilation of fertilizer within the culture.

The method is used in the following cases:

  • for use on fertile soil and in fruit-bearing plants, to enhance the growth of the root system;
  • to increase the size of the plant;
  • to regularly enrich the soil with nutrition in order to avoid damaging the plant factors;
  • when potassium deficiency is detected in the soil;
  • to grow a crop planted not in a timely manner.

This method provides labor and time savings.

Garden application

In this method, fertilizers can also be poured on the soil with the only difference that it should be done after the formation of beds, which need to be dug up and the granules poured to the bottom so that they are 3-5 cm below the seeds. And also sprinkle near seeds or seedlings before planting in a radius of 5-8 cm.

The method is applied:

  • to plants that are usually planted by the method of beds, or with wide intervals between rows;
  • when fertilizer needs to be applied in small quantities in the region where plants with a weak root system and in soil with low productivity are grown.

Many studies show that applying this method is the best. When fertilizer is concentrated in large quantities near the plant, its weakened roots can easily extract nutrients and establish its growth.

Use of sprinkler on top and sides

The grown plants are irrigated from above and on the sides by spraying after they rise to the surface of the soil. This method is mainly used in early spring.

Spraying on leaves

Commercial fertilizers are usually applied to the leaves in the form of a solution, when a trace element deficiency is observed in fruit trees and shrubs.Beneficial substances are absorbed through the cuticle or pores of the leaves. The method is used in a region with a very hot or cold climate. This method can be a good protective tool so that the plant does not hurt.

Application of irrigation with water for irrigation

In this method, fertilizer mixed with irrigation water is given to the soil. Such irrigation is used mainly with plants such as citrus fruits, sugar beets, clover.

Urea: Pros and Cons of Using

So to summarize.

The benefits of using urea are as follows:

  1. Easily accessible. The cost of urea is relatively cheaper than other nitrogen fertilizers, because the cost of production is lower. It is less heavy and more concentrated than other fertilizers. Therefore, the cost of transportation, storage and processing of urea is also lower than in other nitrogen fertilizers. Being cheaper and more efficient, urea fertilizer is a viable option for increasing plant and agricultural growth.
  2. Higher nutrient density. As mentioned earlier, urea has a higher nitrogen content of 46 percent, which is more than other nitrogenous fertilizers such as ammonium nitrate or ammonium sulfate.
  3. Unlike other nitrogen fertilizers, urea fertilizer is not flammable. However, this fertilizer must be stored below room temperature to prevent its decomposition, loss of effectiveness and nutrients.
  4. Fast assimilation. Urea is a fast-acting fertilizer and eliminates the lack of nitrogen in plants within 20-40 days after application - a time frame that cannot compete with other nitrogen fertilizers. However, the disadvantage of rapid absorption is that the urea used is depleted more quickly and may require more frequent reuse compared to other fertilizers.

Minuses:

  1. Evaporation. When urea spreads on the surface of the soil, it quickly reacts with moisture, which turns the enzyme urease into ammonium bicarbonate. The whole process takes 48 hours, after which ammonia begins to disappear. If this is not prevented, most of the ammonia will simply evaporate. Loss of 50-70 percent of nitrogen by volatilization will have an almost useless application of urea fertilizer and, therefore, methods should be used to preserve nitrogen in the soil, and not just apply it to the surface.
  2. Increased soil acidity. Urea, as a rule, acidifies the soil more than other nitrogen fertilizers. The reason is that it produces higher concentrations of ammonia, which in turn causes the soil to become more acidic. Increased acidification gradually increases soil fertility and its ability to produce a healthy crop in the coming seasons.
  3. If the recommended concentration is exceeded, urea fertilizer can burn plants and kill them. Therefore, this fertilizer should be used in limited quantities and infrequently reused. Hygroscopic fertilizers for urea absorb moisture and are known to be highly soluble in water. Therefore, it is necessary that the urea be sealed in sealed packages to prevent moisture from interacting with this organic compound.
  4. Unstable room temperature. Urea tends to decompose rapidly at room temperature, greater than that of other solid nitrogen fertilizers, which leads to a loss in the quantity and quality of the crop.
  5. Pests. Soil fertilized with nitrogen becomes more desirable for pests, since they feed on nitrogen in plants in the same way as a planted crop. To control pests in these conditions, you may need to use additional chemistry.

Weighing the aforementioned pros and cons of urea, it is not surprising why this fertilizer is becoming increasingly popular around the world.

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