It is found in soil. Magnesium absorption by plants is conditioned by three main factors: the amount of land accessible, magnesium interactions with other elements and requirements of the plant. Insufficient magnesium produces necrosis of leaves. Magnesium accumulate in seeds, formed with phosphoric acid, fitina.
A small amount of magnesium cause lifting of malic acid content and decreases in citric acid in plants.
Plants which include magnesium are required in terms of vital assets and are more resistant to the various adverse environmental conditions.
Symptoms of magnesium deficiency resembles somewhat with the lack of potassium. Parenchyma between the ribs and on the leaf begins to take yellow-orange, red, purple and violet, appear chlorosis green spots open. With increasing deficiencies, and often blur into chlorosis spots leaves curl.
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.