Nitrogen (N) in it’s natural form is an odorless, colorless gas and surprisingly makes up around 79% of the air we breathe! Its generally unreactive and the atoms exist in pairs as N2 molecules as a gas at room temperature. Nitrogen has common use in its cold, liquid state to fast freeze things.
Although Nitrogen is fairly unreactive it forms bonds with Ammonia (NH3) and Oxygen (Nitrous oxide NO3), both of which plants readily uptake and use.
Nitrogen is the basis of amino acid molecules, which are commonly referred to as ‘the building blocks of life’ as they make proteins and even DNA. If nitrogen did not exist, life as we know it would be completely different.
For this reason plants require a relatively large amount of nitrogen and although it is abundant in the air, plants cannot simply breathe it in like humans can. Alternatively, it must be taken in through the roots, usually in the form of ammonium (NH3) or as nitrate (NO3). Once the plant has uptaken nitrogen in the available form, it uses it to create amino acids, in turn creating proteins which then create vital chlorophyll and other plant matter. When in the form of nitrate, it is mobile and reusable in plants. Meaning that if there is a shortage of available nitrogen, the plant will use nitrogen in older parts of the plant (essentially cannibalizing itself). When selecting the nutrient line you’d like to use for your grow, look for a line that uses nitrates as one of its main forms of nitrogen, it will be most beneficial!
Plants can relocate Nitrogen within themselves. When there is a shortage of Nitrogen, plants will move it from older, lower leaves, and send it to the top of itself to build new growth. A deficiency begins with yellowing leaves at the bottom of the plant. The yellowing progresses up the plant as the deficiency continues and leaves may begin to fall off. Flowering may be triggered prematurely as the plant tries to reproduce before it is too late.
An overdose of Nitrogen first shows itself as very lush dark-green leaves. The dark greenness moves up the plant. The leaves may form a “claw” with burnt tips. The leaves and stems of the plant may become weak and brittle because the salt content within the plant makes it difficult to transport water and fluids around itself. The crop will often have a grassy taste of chlorophyll and/or salty.