Nitrogen Nutrient Functions

Plants require nitrogen to grow, develop, and reproduce. Despite the fact that nitrogen is one of the most abundant elements on the planet, nitrogen insufficiency is the most prevalent nutritional problem affecting plants globally, as nitrogen from the atmosphere and the earth’s crust are not immediately available to plants.

Above-ground tissues of healthy plants usually contain 3 to 4% nitrogen. Compared to other nutrients, this is a very high concentration. The only other nutrients present in larger amounts are carbon, hydrogen, and oxygen, which do not play a substantial role in most soil fertility management schemes.

Because nitrogen is a key component of chlorophyll, the molecule that allows plants to convert sunlight into sugars from water and carbon dioxide, it is extremely important (i.e., photosynthesis).

Amino acids, the building blocks of proteins, include a lot of nitrogen as well. Plants wither and perish without proteins. Many of the biochemical reactions on which life is built are made possible by proteins, which act as structural units in plant cells and as enzymes in other organisms.

Nitrogen is found in ATP and other energy-transfer molecules (adenosine triphosphate). The energy created during metabolism is conserved and used by cells thanks to ATP. Finally, nitrogen is found in nucleic acids, such as DNA, which is the genetic material that permits cells (and eventually whole plants) to grow and reproduce.

Nitrogen in Soil

Organic nitrogen molecules, ammonium (NH4+) ions, and nitrate (NO3) ions are the three main types of nitrogen in the soil.

95 to 99 per cent of the theoretically accessible nitrogen in the soil is in organic forms at any given moment either in plant and animal wastes, relatively stable soil organic matter, or living soil organisms, primarily microbes like bacteria. Although this nitrogen is not directly available to plants, microbes can transform some of it into usable forms. Organic nitrogen may exist in trace amounts of insoluble organic molecules like urea, making it marginally available to plants.

The inorganic forms NH4+ and NO3 make up the majority of nitrogen accessible to plants. Ammonium ions attach to the negatively charged cation exchange complex (CEC) in the soil and act similarly to other cations. Because of their negative charges, nitrate ions do not bind to soil solids but instead exist dissolved in soil water or precipitated as soluble salts in dry environments.

How Do Plants Take Nitrogen?

Plants do not obtain nitrogen from the air directly. Despite the fact that nitrogen is the most abundant element in the air, every nitrogen atom forms molecular nitrogen, N2, by being triple-bonded to another nitrogen atom. This triple bond is extremely strong, and it is extremely difficult to break it. As a result, despite the abundance of nitrogen in the air, splitting the nitrogen molecule to obtain the raw atoms that a plant may use is energetically unfavourable.

Because of its strong triple bond, molecular nitrogen has a difficult time reacting with other compounds. This is part of the reason why there is so much nitrogen in the air in the first place. Additionally, the nitrogen molecule’s stability and symmetry make it difficult for distinct nitrogen molecules to connect to one another.

Because molecular nitrogen may be chilled to extremely low temperatures before becoming a liquid, liquid nitrogen is an excellent cryogenic liquid.” Nitrogen fixation” refers to the process of separating the two atoms in a nitrogen molecule. Plants obtain nitrogen from the soil, where bacteria and archaea have previously fixed it.

Bacteria and archaea can convert molecular nitrogen from the air (N2) to ammonia (NH3), breaking the molecular nitrogen triple bond.” Diazotrophs” are organisms that do this. Various bacteria then convert ammonia to more plant-friendly nitrogen molecules. Plants obtain nitrogen from the air indirectly through microorganisms in the soil and certain plant roots in this manner.

It’s worth noting that high-energy solar radiation and lightning can fracture the nitrogen molecule, thereby fixing nitrogen in the atmosphere. However, when compared to the quantity fixed by diazotrophs in the soil, the amount of nitrogen fixed by lightning and solar radiation is negligible.

Essential Nutrients in Plants

Scientists found 16 critical nutrients and categorised them based on how much each plant requires: 

Primary nutrients, also known as macronutrients, are the ones that are needed in the most significant amounts. Carbon, hydrogen, nitrogen, oxygen, phosphorus, and potassium are the elements that make up the elements carbon, hydrogen, nitrogen, oxygen, and phosphorus.

In comparison to the major necessary nutrients, secondary nutrients are frequently required at moderate levels. Calcium, magnesium, and sulphur serve as secondary nutrients.

When compared to primary or secondary nutrients, micro- or trace nutrients are required in very small amounts. Boron, chlorine, copper, iron, manganese, molybdenum, and zinc are only a few of the micronutrients.

Conclusion

Nitrogen, Chemical symbol N, atomic number 7, and a gaseous chemical element. It is a colorless, odorless, and tasteless gas that makes up 78 percent of the Earth’s atmosphere and is found in all living things. It’s used as an inert atmosphere or to dilute other gasses because it’s nearly unreactive diatomic molecule N2. It is used to concentrate liquid samples and reduce their volume. The chemical sector relies on nitrogen as well. Fertilisers, nitric acid, nylon, colours, and explosives are all made with it.