Nitrogen is one of the essential elements for growing huge and potent plants. Without it, plants cannot carry out photosynthesis, let alone survive in the long run. Its deficiency or abundance is also harmful to a plant’s growth. – Gro Indoor
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Role of Nitrogen in Promoting Plants Growth and Health

by 09 Apr 2023

Role of Nitrogen in Promoting Plants Growth and Health

Hormones control many functions in the human body. For instance, the thyroid hormone is responsible for iodine regulation. Similarly, growth hormone is responsible for our overall growth. We humans have different heights that depend on the functionality of our growth hormone.

When we visit a garden, we see plants of different heights, some being stunt while other plants are standing tall. Plants do not have hormones, but some nutrients play a vital role in their growth and well-being. If we remove photosynthesis from plants, we will barely find enough plants to keep us alive or add beauty to our earth.

Plants can perform photosynthesis because of the chlorophyll that is responsible for this process. Phosphorus provides the energy required for photosynthesis, but Nitrogen is the essence of this whole oxygen-releasing process. If we analyze the simplest definition of photosynthesis, it says that it is a process that plants use to prepare their food.

Nitrogen is a vital component of chlorophyll, but it is also a part of the amino acids that build the plant's proteins. Healthy plants often have 3-4% nitrogen in above-ground tissues. The concentration of Nitrogen is much higher in healthy plants than in other essential nutrients.

Are you planning to grow potent and huge plants in your garden? You cannot achieve your goal if you lack knowledge about Nitrogen's role in the plant's growth. Plants extract Nitrogen from the soil through their roots, both in the hydroponic or growing medium. Microorganisms and insects that live in soil survive on the nitrogen content of the soil, leaving a minimum amount of this nutrient for plants. The minimum amounts of Nitrogen in the soil are insufficient to fulfill the plant's requirement, making it mandatory to compensate for it through supplements.

What does Nitrogen do?

Reading the emphasis on the importance of Nitrogen for a plant, one might question its role. Nitrogen is an indispensable nutrient for the plant's growth, propagation, and development. It is one of the most abundant elements on the earth, yet its nutritional deficiency is very common, affecting various plants worldwide. Nitrogen is present in all parts of plants, including plant tissues, leaves, grains, and roots. Nitrogen comprises part of the chlorophyll in leaves and the "green" part of the stems and leaves. In the absence of chlorophyll, a plant can't convert sunlight into usable energy.

Nitrogen regulates the growth and development of plant tissue. In plants with protein, their fruits, grain, and seeds can also store Nitrogen. The roots of a plant use different enzymes for the absorption and transportation of nutrients. These enzymes also have Nitrogen that helps the water to suck up water from the soil to grow and stay healthy. Not every plant's requirements are the same for Nitrogen. Their quantity varies depending on the species of the plants and their growth stage.

Significance of Nitrogen in a Vegetative State

When we say the word vegetative state, it refers to the phase of plant growth that initiates right after germination and before flowering. During this stage majority of a plant's foliage truly flourishes. Nitrogen is a quick source of energy, and it is the most significant component of the vegetative stage. The vegetative stage regulates the strength and health of the leaves' tissues. Nitrogen also aids in the development of roots, stems, and foliage in a vegetative state.

Fruits, seeds, and flowers also require Nitrogen, but the quantity is low in the initial vegetative stage. As the flowers continue to grow in the flowering stage, the plant moves away from the stem. It focuses more on the budding of flowers and fruits. The excess Nitrogen in the flowering stage can be harmful to the growth of the plants.

Sources of Nitrogen

Like humans having different food sources, plants can obtain nutrients from different sources, but the three major nitrogen sources are as follows.


One of the most common sources for plants to obtain Nitrogen is ammonium. At atmospheric pressure, it exists in its gaseous state, but it is compressible into liquid. Adding ammonium to soil converts it into nitrate, which makes it easy for the roots to absorb it from the soil. The Nitrogen obtained from ammonium requires more oxygen for its metabolism in roots, where it reacts with sugar for further transportation.


It is the third form of nitrogen fertilizer, and it undergoes changes in three steps before its availability for use. The enzymes present in the soil convert urea into ammonia, where it reacts with the water content of soils to become ammonium. The microorganisms present in soil then convert ammonium into nitrate.


It is the dissolvable form of ammonia and moves as water moves in soil. Nitrates can easily seep from the soil, especially the ones in clay form.

Choosing the Best Form of Nitrogen

Nitrogen fertilizers are usable on plants, but knowing the kind of plant that needs fertilizing and when to do it. If you intend to plant in spring, ammonium sulfate and urea are the best sources of Nitrogen.

Nitrogen Deficiency in Plants

When a plant goes deficient in Nitrogen, the symptoms start to appear on the older and lower leaves, turning yellow. It is one of the most generally known deficiencies found in plants. It is a mobile nutrient. When the older plants start breaking down, the plant transports it to the fresh leaves. The deficiency slowly progresses upwards, and only the leaves at the top will stay green.

On the other hand, the leaves turning yellow will wit and eventually die. The necrosis leaves stars from the tip and moves inward, separating the leaves from the twig. Nitrogen comprises a major part of plant cell tissues. If you notice the new leaves being smaller in size and the overall plant is stunt than its usual height, nitrogen deficiency impacts the growth.

Sign and Symptoms of Nitrogen Deficiency

Other than affecting the overall growth of a plant and leaves turning yellow, the following symptoms can also indicate nitrogen deficiency in plants.

  • Stunted new growth
  • Older leaves getting affected; in severe cases, they droop off
  • Wilting or drooping of leaves
  • Leaves turning yellow
  • Leaves start turning yellow from the tip and moving inwards to the veins.

How Can You Compensate Nitrogen Deficiency?

When the human body lacks some minerals or other nutrients, they take supplementary medicines to fulfill the requirement. Similarly, plants also need some external material to overcome the deficiency of their nutrients. Since the pH factor of soil plays a significant role in the development and health of a plant. If your plants are becoming deficient in Nitrogen, check for pH imbalance. A pH imbalance hinders the absorption of nutrients from the soil.

Maintaining an optimum pH in both the hydroponic and growing mediums is vital to promote better plant growth. The ideal pH range for most plants ranges between 5.5-6.5. Roots are the primary part of plants when it comes to nutrient absorption, but it is only possible when the nutrients are in their soluble form. The ideal pH range makes the nutrient soluble and available for the roots to absorb.

pH range outside the recommended range makes it challenging for the roots to absorb nutrients besides being present abundantly in soil. If the pH levels are in their optimal range and nitrogen deficiency is still persistent, it is time to check for nutrient imbalance or toxicity. The nutrients in plants interact in two ways, i.e., synergistic or antagonistic. The word synergic points to the cooperative interaction between nutrients, and the antagonist refers to the interference or inhibition of interaction.

Feeding one nutrient in excessive quantity leads to locking out other nutrients essential for plants. As a grower, if you have made the checklist for feeding for a plant, the nutrient imbalance will not occur.

Size of Pots

The container or pots that we use for our plants also affects the capacity of nutrients in the soil. The undersized containers for a growing plant are a common mistake made by indoor plant growers. Undersized containers do not have much room for soil and nutrients, and they do not stay for long in the soil. If a plant's size requires more nutrients and is in an undersized container, it will quickly soak up all the nutrients.

There will be no nutrients left for other processes leading to the deficiency of nutrients. If you notice that the container is too small for a plant, you can transplant a plant until the third week of flowering into a better-sized pot to facilitate its growth and nutrient availability.

Assessing the Quality of Growing Medium

Besides removing the pH and nutrient imbalance, if nitrogen deficiency is still there, the next thing to do is check your growing medium. It is an easily correctible measure to treat nitrogen deficiency. Using the topsoil is not ideal as many growers are unaware of its contents and the nutrients it has, and they do not offer enough room for aeration and drainage. Using quality grade horticultural soil, other mediums, or optimum nutrients eliminates excess or deficiency chances. Are you looking for what kind of soil you should use? Refer to our best soil of the year list to rule out your soil-related issues.

Switch to a Nitrogen-Rich Fertilizer

If you have ruled out the pH issues, mediated the nutrient imbalance, changed the pot size, and even fixed the growing medium that doesn't work, switch fertilizer. Fertilizers and nutrient supplementation play a significant role in a plant's growth. Adding fertilizer to the soil boosts growth, making the plants grow faster than their roots can absorb the nutrients from the soil. Many gardeners intend to remediate nitrogen deficiency in its initial stages quickly.

All-in-one solutions come in handy to overcome the deficiency as they promote foliage growth, healthier and more abundant blooms, and fruits. Before you pick up your fertilizer, verify the pH range to be 5.5-6.8. You can also apply all nitrogen-rich soil, hydroponic nutrients, or amendments.

Knowing the Nitrogen-Rich Nutrients

Just like a packet of our favorite snacks has its nutrient displayed on its packaging, the plant supplement also tells you about what’s inside it. Nitrogen, phosphorus, and potassium are three key components of any plant-related supplement. NPK ratios are visible on every packet letting the user know about the quantities and decide what to choose.

One of the easiest ways to identify nitrogen-rich nutrients is to look for the number written adjacent to the letter N. The higher the N-number, the higher the quantity of Nitrogen in that supplement. In case you are still doubtful, MSDS (material safety data sheet) can help you pick the right supplement.

What Happens in Nitrogen Toxicity?

When we as humans consume excessive junk food, it results in a condition known as obesity. Likewise, any nutrients in surplus amounts in plants lead to toxicity. Nutrient toxicity is common in plants, and one of the most common nutrient toxicity results from overfeeding Nitrogen. As much as Nitrogen is essential for healthy plants, its excessive amounts can adversely affect a plant's health.

Nitrogen toxicity is common in hydroponic grows as compared to other growing mediums. Excessive Nitrogen damages the plants as much as nitrogen deficiency. The toxicity symptoms vary depending on the plant's type, but the most common toxicity sign is extremely dark green coloration in plants. The leaf tips appear burned or brownish, and some may turn yellow if they have access to Nitrogen but lacks other nutrients.

While evaluating your plant's toxicity, it is vital to begin by ruling out already present issues. For instance, make sure that you are not overwatering or underwatering your plants. The watering issue is more common in-ground plants or those in a container than in hydroponic grow. In dealing with plants in hydroponic grow, it is essential to ensure that the solution you are using is well-oxygenated with air stones. Also, check for the temperature and pH to be in normal or recommended ranges.

How to Eradicate Nitrogen Toxicity?

After ruling out all the possible issues that can affect your plant growth, if it still shows no improvement, then it's time to fix nitrogen toxicity. One of the common solutions to reduce the toxicity is to cut down the amount of Nitrogen or stop feeding it. It is one of the solutions but removing the causative element alone is not enough.

Check the solution to ensure that all the nutrients fall in their recommended ranges for a plant’s growth. In case it needs pH balancing, dilute it with fresh water or replace the reservoir with water and fresh nutrients to start again.

It is vital to opt for reservoir change if you are dealing with toxicity in the flowering stages. In case you are growing plants in the soil, keep an eye on how you are fertilizing the soil. Avoid feeding nitrogen-rich fertilizers (both synthetic and others like chicken manure) as our goal is to reduce toxicity instead of increasing it.

If you are not fertilizing your soil and the plants are still getting the adverse impact, try to filter out some water from your soil and pour it into the area where new plants are growing. Doing so will help you flush out some of the nitrogen content from the abundant reservoirs present in the soil.


Are you willing to learn more about the nutrients and their impact on plants? Our nutrient deficiency series is here to answer all the questions that you have in mind. We can assay that Nitrogen is not only vital in maintaining the plant's function, but it is also necessary for life.

Nitrogen is present in plants more than any other element (except oxygen, hydrogen, and carbon). When working in your garden, consider Nitrogen's role and its effect on the plant to instantly identify the signs of toxicity and deficiency and instantly take corrective measures.

Get your hands on Nitrogen supplements at today!

Sep 30th 2022
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