Nitrogen plays a particularly important role for the growth and development of crops. Because it has both a structural role and is involved in metabolic and energy processes.
Nitrogen is necessary for plant growth more than any other macronutrient, therefore it determines the yield and quality of the harvest.
The roots absorb Nitrogen in 2 forms: nitrate nitrogen (NO3-) and ammonium nitrogen (NH4+) in the soil.
In addition, the processes of resolving organic compounds of soil microorganisms and the amount of fertilizer annually have provided a fairly large amount of Nitrogen for plants.
What is nitrogen?
Nitrogen (N) is a chemical element in order of 7 under normal conditions it is a colorless, odorless, tasteless and quite inert gas that does not participate in chemical reactions at room temperature.
Nitrogen accounts for about 78.09% of earth’s atmosphere. Nitrogen is an essential mineral nutritional element of plants and they exist in various forms.
For nitrogen crops absorbed from the environment by the roots of plants in the form of NH4+ and NO3– especially some plants that are born with nitrogen-fixing bacteria that can convert N2 in the air for use.
What role does nitrogen play for plants?
Nitrogen plays a particularly important role for the growth and development of crops. Its decision on harvest yield and quality.
Nitrogen is involved in the composition of protein molecules, nucleic acids, chlorophyll, ATP, etc
When nitrogen deficiency will reduce protein synthesis, from which the growth of the muscles is reduced, appearing light yellow on the leaves.
Light yellow color appears first in old leaves. It happens due to the mobilization and movement of ions in the plant.
Nitrogen is the constituent of proteins – enzymes, coenzyme and ATP. So nitrogen participates in the regulate of metabolic processes in the plant body through catalyst activity, energy supply and regulates the hydrated state of protein molecules in the cell.
Why do plants need nitrogen?
In the first half of the life of the plant, a plant accounts for 80% of the amount of nitrogen required for the entire life cycle of the plant.
Nitrogen is the composition of most plant substances: proteins, nucleic acids, photolyfix pigments, energy reserve compounds: ADP, ATP, growth conditioners. Nitrogen plays both a structural role and participates in metabolism and energy.
Plants in need of N are very large, enough nitrogen plants grow strong, fruits are numerous and large.
On the contrary, when the N-plant deficiency stops growing, the leaves turn pale yellow, the plant now accumulates more carbohydrates because it is not used to synthesize compounds containing N. Nitrogen deficiency is worse when the phosphorus is low.
So it can be seen that plants desperately need nitrogen to ensure that the plant grows and grows well.
Where can plants get nitrogen?
Plants can take nitrogen from the air or the soil. In nitrogen air exists mainly in the form of molecular nitrogen (N2), nitrogen-absorbing crops have been converted into NH3 form through the activity of nitrogen fixed microorganisms.
Soil nitrogen includes mineral nitrogen (Inorganic nitrogen, including NO3- and NH4+) in mineral salts such as nitrate salts, nitrite salts, ammonium salts, and organic nitrogen in animals, plants, and microorganism.
Crops can directly absorb mineral nitrogen, while organic nitrogen in the organism needs to be absorbed by microorganisms converted into NO3– and NH4+ for plants to absorb.
In addition, plants can absorb nitrogen from some types of synthetic nitrogen fertilizers used such as: Ammonium nitrate fertilizer (NH4NO3), Ammonium sulfate or SA (NH4)2SO4, chloride nitrogen fertilizer (NH4Cl), so on.
Nitrogen Fixation – ever wonder how it works? Watch this short video:
How do plants use nitrogen?
Nitrogen that is converted through NO3 – reduction and NH3 assimilation process.
For NO3– reduction: sucked from the soil both forms of oxidative nitrogen (NO3–) and nitrogen reduction (NH4+), but the plant only needs the form NH4+ to form amino acids.
So the first thing that the plant has to do is to transform the NO3– into NH4+ to the Reductase enzyme system. Mo and Fe activate the enzymes involved in the upper reduction process.
The ammonification process occurs in the following steps:
NO3– (Nitrates) → NO2– (Nitrite) → NH4+ (Ammonium)
For NH3 assimilation process: Respiratory process of the plant produces serosacids (R-COOH), and thanks to the nitrogen exchange of these acidic serosacids adds NH2 root to the amino acids.
There are 4 reactions to the formation of amino acids. The following are the de-amino reactions to the formation of amino acids:
+ Xetoglutaric + NH3 + 2 H+→ Glutamine + H2O
+ Pyruvic acid + NH3+ 2 H+ → Alanin + H2O
+ Fumaric acid + NH3 → Aspartic
+ Oxaloacetic acid + NH3 + 2H+→ Aspartic + H2O
And then there are the amine metabolism reactions to form 20 amino acids and from these amino acids plants can produce a multitude of proteins and other foreign compounds of plants.
The newly formed amino acids will combine with NH3 to form amits, which detoxify and reserve N for plants when plant tissue is excess NH3.
Cautions with nitrogen?
Nitrogen in NO, NO2 in the air is toxic to plants. Besides, this can be excess nitrogen because in the process of human cultivation add nitrogen from too much fertilizer, leading to too strong growth of plants, fast-growing stems and leaves.
But plants are susceptible to pests and external conditions, productivity decreases.
Thus, it can be seen that nitrogen plays an extremely important role in the growth and development of plants. Enough nitrogen crops will grow strongly, high crop yields, on the contrary when excess or lack of nitrogen will reduce crop yields.
Therefore, besides the crop absorbing nitrogen in nature, humans also need to provide the plant with a sufficient amount of nitrogen to meet the growth and development needs of the plant.