Physiology of N in plants:

It is difficult to find some physiological process in the plant in which this element does not intervene, among the most important are:

• It is the most important element in proteins and amino acids present in the plant kingdom.
• It is a component of chlorophyll, the molecule responsible for the conversion of light energy into chemistry.
• Main element in the nucleic acid chains.
• Main element of photoassimilates (vitamins, sugars, cellulose, starch, lipids …).
• It is a component of coenzymes and enzymes, that is, of the processes of activation and catalysis of the biochemical reactions of plants.

In terms of agriculture N isresponsible for the plants “vegetative” growth, that is, cell division, growth, sprouting and structural formation.

So much so that in excessive contributions of N or excessive availability of the element, N can create an imbalance that supposes a growth of vertical stems, an excessive elongation between knots, a decrease of lateral ramifications, a special difficulty for the formation of floral bouquets, including fruit setting, preventing photoassimilates from being directed to the main natural recipient of the plant, that is, the fruit; in short, a disorder that needs assessment and correction in terms of the plants nutritional balance. This type of disorder is frequently seen in areas where mineral fertilizers with high percentages of easily assimilable N, has been excessively applied.

On the other hand, given its importance, N deficiencies can have serious consequences for the plant; in general terms:

• Poor vegetative growth, lack of vigor, height.
• Chlorosis, general yellowing especially in adult leaves, although it is also visible in meristems.
• Some plants such as tomatoes or some varieties of corn show a purplish coloration caused by the accumulation of anthocyanin pigments.
• Less leaf growth compared to root development.
• Decrease in protein synthesis.
• Poor flowering, bad fruit setting, .
• Less resistance to situations of abiotic stress.