### element | nitrogen:

Adequate nitrogen
* ensures that nitrogen is present for production of new leaves.
* gives a plant healthy green leaves and strong growth.

Ammoniacal nitrogen
* favors disease severity compared to nitrate nitrogen.
* includes all the ammonium forms of nitrogen in the fertilizer.

Atmospheric nitrogen
* Some atmospheric nitrogen has effects.
* is converted into a form usable to plants inside the nodule
  - the largest pool of available nitrogen in terrestrial ecosystems
* major source of nitrogen in soils.

### element | nitrogen:

Excess nitrogen
* Some excess nitrogen comes from proteins.
* can also delay and prevent flower and fruit formation in other crops.
* can cause fruit drop
  - lush stands with high humidity in the canopy
  - overstimulation of growth of aquatic plants and algae
  - succulent growth, leading to insect, disease and other problems
  - harm the circulatory systems of fish
  - leach through soil into groundwater
  - lead to the loss of fine root biomass and deficiencies in other nutrients
  - look like a deficiency
  - move downward through the soil as nitrate, causing pollution of groundwater
* causes branching and hairy, fibrous roots
  - lush growth and late plants
  - the pile to lose nitrogen to the atmosphere as ammonia gas
* contaminates groundwater.
* encourages foliar growth at the expense of flowers.
* has the potential to severely alter the natural balance of an ecosystem.
* increases the thatch and reduces cold and drought tolerance of centipedegrass.
* is also a problem at sea, where it causes algal blooms, and oxygen depletion
  - converted into urea in the liver
  - excreted from the body
* leads to algal blooms which in turn leads to dangerously low levels of oxygen.
* promotes excess algal growth, resulting in cultural eutrophication
  - seedling growth and succulence rather than maturation
* raises nectarine susceptibility to disease and insects.

### element | nitrogen:

Excessive nitrogen
* can cause the foliage to overgrow and hide the flowers
  - contribute to decreased oil content in the seed
  - lead to higher levels of lodging and disease
* can result in foliage production at the expense of flower production
  - succulent growth with dark green color and weak spindly stems
* creates weak spindly growth, resulting in few flowers and fruits.
* encourages high vegetative vigor, which causes a dense canopy to be produced.
* favors aphid reproduction.
* is often a reason flowers fail to bloom properly
  - the most common cause of lush foliage with no tomato fruits in the garden
* reduces sugar per ton and increases sugar loss to molasses
  - the dry matter of potatoes and processing quality

High nitrogen
* causes rapid foliage growth at the expense of the bloom
  - stress
* is shown in red and low nitrogen in blue.
* promotes foliage growth, and excessive foliage requires more water.
* results in lush growth that attracts egg-laying female moths.

Inorganic nitrogen
* comes from minerals, and is added to soil from precipitation, or as fertilizers.
* depresses crop yields on poor land, but enhances yields on fertile land.
* is the form that is taken up by the plant root system and used for growth.
* regimes in an Alabama wetland.

Ionized nitrogen
* gives off blue light while neutral nitrogen glows red.
* glows blue or red.