In What Form do Plants Absorb Nitrogen?

In What Form do Plants Absorb Nitrogen? Nitrogen is essential for all plants’ survival and occurs in a variety of forms. Although nitrogen makes up the majority of the atmosphere, it exists in the form of a gas known as dinitrogen N2. Plants are unable to employ this form. Dinitrogen, commonly known as atmospheric nitrogen, can be found in soil. In addition to dinitrogen, the soil contains additional inorganic and organic components. Organic nitrogen accounts for a sizable portion of total nitrogen in the soil. Plants, on the other hand, can only use extremely particular inorganic forms of nitrogen. The table covers the most common soil forms as well as the most common plant forms.

Impact on water quality

Nitrogen becomes a concern to water quality when nitrogen in the soil is converted to the nitrate (NO₃^–) form. This is because nitrate is very mobile and easily moves with water. The concern of nitrates and water quality is generally directed at groundwater. However, nitrates can also enter surface waters such as ponds, streams and rivers. Nitrates in the soil result from natural biological processes associated with the decomposition of plant residues and organic matter. Nitrates can also come from animal manure and nitrogen fertilizers.

Whether nitrates actually enter groundwater depends on underlying soil and/or bedrock conditions, as well as depth to groundwater. If depth to groundwater is shallow and the underlying soil is sandy, the potential for nitrates to enter groundwater is relatively high. However, if depth to groundwater is deep and the underlying soil is heavy clay, groundwater contamination from nitrates is not likely.

Once nitrates get into the groundwater, the greatest concerns are for infants less than one year old and for young or pregnant animals. High levels of nitrates can be toxic to newborns, causing anoxia, or internal suffocation. Seek alternative water sources if nitrate levels exceed the health standard of 10 ppm nitrate-N. Do not boil water to eliminate nitrates. It increases nitrate levels rather than decreasing them. The most common symptom of nitrate poisoning in babies is a bluish color to the skin, particularly around the baby’s eyes and mouth. These symptoms of nitrate toxicity are commonly referred to as the “blue-baby” syndrome.

Why Nitrogen is Needed by Plants

Nitrogen is an essential macronutrient required by plants for healthy growth and development. Here are some reasons why nitrogen is needed by plants:

1. Protein synthesis: Nitrogen is a key component of amino acids, which are the building blocks of proteins. Proteins are essential for plant growth and development, as they play a role in the structure and function of cells, enzymes, and hormones.
2. Chlorophyll production: Chlorophyll is the pigment that gives plants their green color and is necessary for photosynthesis, the process by which plants produce energy from sunlight. Nitrogen is needed to produce chlorophyll, and a deficiency of nitrogen can result in yellowing of leaves and decreased photosynthesis.
3. DNA and RNA synthesis: Nitrogen is also a component of nucleic acids, which are the genetic material of plants. Nitrogen is required for DNA and RNA synthesis, which are essential for cell division, growth, and development.
4. Increased yield: Nitrogen is one of the most limiting nutrients for plant growth, and adding nitrogen fertilizers can increase crop yields. However, it is important to manage nitrogen fertilizers properly to avoid environmental pollution and reduce costs.
5. Resistance to stress: Nitrogen also plays a role in the plant’s ability to withstand stress, such as drought or disease. A deficiency of nitrogen can make plants more susceptible to stress, while adequate nitrogen can help plants cope with stress and recover more quickly.

Nitrogen is a crucial macronutrient required by plants for healthy growth and development. It plays a role in protein synthesis, chlorophyll production, DNA and RNA synthesis, increased yield, and resistance to stress. Proper management of nitrogen fertilizers is important to ensure optimal plant growth while minimizing negative environmental impacts.

How Nitrogen is Absorbed by Plants: Different Forms

1. Nitrate (NO3-): Nitrate is the most common form of nitrogen absorbed by plants. Nitrate is produced in the soil through the process of nitrification, which involves the conversion of ammonium ions to nitrate by nitrifying bacteria. Nitrate is highly soluble in water and is easily taken up by plant roots. Once inside the plant, nitrate is converted into amino acids, which are the building blocks of proteins.
2. Ammonium (NH4+): Ammonium is another form of nitrogen that can be absorbed by plants. Unlike nitrate, ammonium is not produced through the process of nitrification, but rather through the mineralization of organic matter in the soil. Ammonium is less soluble in water than nitrate and is taken up by plant roots through a specific transport system. Once inside the plant, ammonium is converted into amino acids.
3. Urea: Urea is a common nitrogen fertilizer used in agriculture. It is a water-soluble compound that can be absorbed by plant roots. Once inside the plant, urea is hydrolyzed into ammonium ions and carbon dioxide. The ammonium ions are then converted into amino acids.
4. Organic Nitrogen: Organic nitrogen is nitrogen that is present in complex organic molecules, such as proteins, nucleic acids, and amino acids. Plants cannot directly absorb organic nitrogen. Instead, it must first be broken down into inorganic forms, such as ammonium or nitrate, by soil microorganisms through the process of mineralization.

Video: Plant Nitrogen Uptake and Assimilation

Nitrogen is absorbed by plants in a variety of forms, including nitrate, ammonium, urea, and organic nitrogen. Nitrate is the most often absorbed type of nitrogen by plants, while ammonium is less common but still vital. Organic nitrogen must be broken down by soil microorganisms before it can be taken by plants, and urea is a nitrogen fertilizer extensively used in agriculture. We can better control our agricultural methods to promote optimal plant development and productivity if we understand the many kinds of nitrogen available to plants.