Type: primary macronutrient
Nitrogen metabolism is a major factor in stem and leaf growth (vegetative growth). Nitrogen is a key element in the structure of amino acids, the molecules which make up proteins. . Chlorophyll, genetic material (for example, DNA), and numerous enzymes and plant hormones contain nitrogen. Hence, N is necessary for many of the plant's life processes.
Given ample N, Cannabis will outgrow practically and plant. Ample nitrogen is associated with fast, lush growth, and the plant requires a steady supply of nitrogen throughout its life. Marijuana's requirements for N are highest during the vegetative growth stages.
Deficiency symptoms: Leaves turn light green to yellow or becomes necrotic and drop off; plants are stunted and secondary shoot development is poor. Usually there is a rapid yellowing and loss of the lower leaves that progresses quickly to the top of the plant unless nitrogen is soon added.
Toxicity symptoms (nitrogen): Plants are stunted, deep green in color, and secondary shoot development is poor. High N causes vegetative growth instead of reproductive bud formation.
Toxicity symptoms (ammonium): Roots turn brown and appear unhealthy, with necrotic root tips; plant growth is decreased; necrotic lesions occur on stems and leaves; vascular browning often occurs in stems and roots; severe chlorsis and stunting of new leaves are symptoms on some plants.
Ammonium toxicity is common in soilless media, in highly acidic media, and under low temperatures. High carbohydrate and potassium levels in the plant can prevent some of the toxicity symptoms in some plants.
Ammonium fertilizers tend to make the soil more acidic, and nitrate fertilizers tend to make the soil more alkaline.
Benefits: Nitrogen plays a very big role in your plants; this one element is directly responsible for production of chlorophyll, photosynthesis, Amino Acids, which are the building block of Proteins. The myriad of enzymes which help the plants growth in leaves stems and the how well the vigour of your plants is.
Nitrogen and Magnesium get confused. The best way to tell them apart is, nitrogen deficiency starts around the tips and works its way to the back of the leaves,
where a magnesium deficiency will cover the entire outer part of the leave and make the entire leaves yellow leaving the veins to stay green. If your plants are having a slow growth rate and have yellowing of the leaves, then most likely itʼs a nitrogen deficiency.
Towards the middle to end of flowering stages, the plant will show a nitrogen deficiency almost always. This process is completely normal and just let the plant naturally yellow out as it uses it's stored nutrients. This actually helps you by getting ready for final flushing and then harvesting. At this point DO NOT not use nitrogen to fix the problem. The yellowing leaves will then eventually drop off after the plant is done with them.
Parts affected by a nitrogen deficiency are: Older foliage, going to whole plant, Petioles (rare) cases.
Now for having too much nitrogen in your growing mediums or soil. The plant will have like an overall DARK green look and have delayed maturity. Due to Nitrogen being involved in vegetative growth, to much nitrogen will result in tall plants with weak stems. New growth will be very lively and plant transpiration will be high, but not always.
Nitrogen toxicity can be seen when there are very very dry conditions almost as if there was a drought, which may show a burning effect. If you give your plants ammonium based nutrients they may show NH4+ toxicity, which will show a smaller plant growth and lesions that occur on stems and roots, leaf margins that will roll downward. Also the big fan leaves will have “the claw” look. The tips will point down but the leaves will stay up as if when you bend your fingers downwards. Leaves can be twisted when growing… mainly new growths. Roots will be under developed along with the slowing of flowering.
Yields will be decreased, because to much nitrogen in early stages of flowering slows down bud growth. Water uptake is slowing down from the vascular breakdown of the plants as well. Too much potassium and nitrogen will lock out calcium as well.
Problems with Nitrogen being locked out by PH troubles. Waterlogged soil and Soil with low organic matter. Nitrogen is a very important element in the plant, all of them are but some are more important than others.