Nitrogen is a quality nutrient because it is part of the makeup of all the plant and animal proteins. The nutritive value of the food we eat is largely dependant on the availability of Nitrogen for plant and animal growth.
Too much can delay flowering and fruiting. Deficiencies can reduce yields, cause yellowing of the leaves and stunt growth.
Functions in plant:
Nitrogen is a major component of proteins, hormones, chlorophyll, vitamins and enzymes essential for plant life. Nitrogen metabolism is a major factor in stem and leaf growth (vegetative growth).