One of the major mineral elements of plant nutrition.
Nitrogen is found in soil so as combinations of organic and inorganic. Total nitrogen content can reach up to 0.5% of total dry substance of the soil, but more often this content oscillates around 0.1%.
Symptoms Enough nitrogen appear clearly in various stages of development. Supplying plants with sufficient amounts of nitrogen causes plants to have smaller and thinner stems. Leaves fall prematurely and ripening fruit is rushed.
One of the characteristic symptoms of nitrogen deficiency is the leaf color change, which is pale green. Yellowing begins at the ribs and extending to the periphery leaves.
Too much nitrogen extends the period of plant vegetation, make the leaves are well developed and dark green.
The main sources of nitrogen available to plants is primarily inorganic and combinations, as nitrates and ammonia.
Phosphorus is found in soil as organic and inorganic compounds. Soil organic phosphorus comes from the decomposition of organic residues from crop residues or organic fertilizers.
Sulfur is present in the soil as organic and mineral.
Organic sulfur is the most important reserves of ground mineralization and progress to a more or less quickly depending on the activity of microorganisms.
Iron must be present in the soil in a form assimilable otherwise occurs deficiency manifested by green-sickness. Iron deficiency is associated with a yellowing of leaves.
Sodium plays a well defined role in vascular bands and fibers that support the plant tissue.
Halophile plants, adopted an environment with high concentrations of sodium, this element is necessary for growth, give a better color of the leaves, increases disease resistance.
Of all the elements, potassium is found in greatest quantity in plants, especially the young, in the form of inorganic salts.
Potassium deficiency is felt more strongly on soils with high salt content of calcium and magnesium and poor aeration. External symptom of potassium deficiency is the leaf color change, that the appearance of brown spots, especially near the extremities of the leaf.