Calcium is taken from the environment. In plant cells and tissues to be present in ionic form and the form of inorganic and organic combinations.
Calcium cells fulfills a structural and functional role.
Excess calcium green-sickness cause plant, due to the solubility and absorption of mineral compounds of iron, manganese.
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.
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.
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.
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.