What is nitrogen and how do plants assimilate it?

Nitrogen is vital for plant growth

Nitrogen is very, very important to plants. In fact, it is so much so that if they did not find it in the soil in which their roots develop, they would have serious growth problems.

But it is also important that we bear in mind that an excess of this nutrient can be harmful to our crops. So Let’s see what is its importance, and how can we know if a plant needs nitrogen.

What is nitrogen?

Cycle of nitrogenCycle of nitrogen

Cycle of nitrogen

Nitrogen is a chemical whose symbol is N. It is present in the air of the atmosphere, in a fairly high percentage (78%), as well as in living beings. It can take several forms: for example, in air it is a gas, while in the soil it is available to plants in the form of nitrates and nitrites.

In addition, it is also present in many foods intended for both humans and their animals, as well as in fertilizers and manures that are used to care for crops.

How do plants assimilate it?

That is a very interesting question, because much of the nitrogen that remains available to plants is absorbed by the soil from the atmosphere. And how does nitrogen pass from the air to the ground? Well, there are two ways: one is through microorganisms (basically they are bacteria that either produce nitrogen, or are responsible for fixing it), and the other is through rains and other meteorological phenomena.

The most effective and fastest way is the first, since as we know it does not rain in all places with the same frequency, and in many places it does not even fall snow. But there is a problem: not all over the planet are the right conditions for microorganisms to produce nitrogen in sufficient quantities for plants. For this reason, it is often necessary to resort to fertilizers so that they grow normally.

Now, how do they assimilate it? Through the roots, and to a lesser extent through the pores of the leaves.

What function does it have in plants?

Plants assimilate nitrogen through roots and leaves

Plants assimilate nitrogen through the roots and leaves.

Nitrogen fulfills several important functions, but they could be summarized in one: growth. It is vital for the cells to multiply and, consequently, it is also vital for the stems, roots, leaves, … in short, all parts of the plant can continue to grow and develop. In addition, it is also very necessary for the seeds, since thanks to this chemical they can remain alive for a longer or shorter time until the proper conditions are given to germinate.

If we want to be more specific, we can say that nitrogen it is necessary for the production of chlorophyll and auxins, as well as for the formation of lignin (a component of wood found in trees and shrubs).

What are the symptoms of a lack or excess of nitrogen in plants?

Fortunately, as this is such a necessary element for plants, it is relatively easy to know when it is missing or excess. Let’s see what the symptoms of each case are:

  • Lack of nitrogen: the leaves turn yellow starting with the old ones, the growth stops, and the stems can become stunted.
  • Nitrogen excess: when they have too much they produce an excess of leaves, a growth perhaps faster but also weaker, they are more sensitive to pests, diseases, drought, etc.

For this reason, It is not good neither to fall short nor to exceed ourselves. The same thing happens with irrigation: as long as we add the amount of water they need and every time they are really thirsty, they will be well hydrated; but if we keep the earth always waterlogged for them, their roots will rot.

Types of fertilizers rich in nitrogen for plants

There are many types of fertilizers rich in nitrogen, but first of all let me tell you that it is very important that you follow the instructions for use that you can read on the product packaging. With that said, let’s see what are some of the ones out there:


Urea is a diamide form of carbonic acid, and therefore it is the product with the highest nitrogen concentration: over 46%. For this reason, we only recommend its use when the plants show a significant delay in their growth, and also have chlorotic leaves.

Buy it here!.

Ammonium nitrate

No products found.

This is a fertilizer with a nitrogen content of between 33 and 34,5%Of that percentage, half is ammonia nitrogen and the other 50% is nitric nitrogen. So, it is very interesting so that the plants can grow normally, as long as it is used responsibly, yes.

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Ammonium sulfate

Ammonium sulfate it also contains sulfur, so it is not only excellent as a fertilizer but also as a fungicide and even to improve the chemical properties of soils with a basic or alkaline pH (pH of 7 or higher).

You want it? Click here!.


Bat guano is rich in nitrogen

Bat guano is rich in nitrogen

El guano It is a compost of organic origin, not in vain, it is the excrement of seabirds or bats. Its composition varies depending on the diet of the animal, as well as the guano itself: the fresher it is at the time of its collection, the more nitrogen it will have, for example.

It is one of the best on the market, since in addition to N it contains phosphorus, potassium, calcium, as well as humic and fulvic acids. Of course, it is very concentrated: even if it is natural, you have to take the dose indicated on the container, neither more nor less; otherwise the roots will burn.

Here you have it liquid and in this link granulated. Get it.

Chemical fertilizers

We are done with the chemicals. Surely you have heard of, or may have even bought, a fertilizer with NPK, that is, with nitrogen, phosphorus and potassium. These are the three most important nutrients for plants, which is why fertilizers that contain them in greater or lesser percentage are sold on the market.

For example, a triple 15 compost contains 15% nitrogen, 15% phosphorus and 15% potassium. If it is a 15-5-30 fertilizer, it means that it contains 15% nitrogen, 5% phosphorus and 30% potassium. And so with everyone. Its use is interesting when we have a type of plant, such as a palm tree or a cactus, and we want to fertilize it with a specific product. for her.

What did you think of this topic? Nitrogen as we have seen is vital, but an excess of this element can cause serious problems for plants, since it makes them weak and vulnerable to pests and others. We hope you have learned a lot about this chemical element and its role in the plant kingdom.

What is nitrogen and how do plants assimilate it?

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