Among all micronutrients, iron is the one that is needed most, being part of the catalytic groups of many redox enzymes of the hemoprotein type whose nucleus is formed by porphyrin found chelating an iron atom. Among this group of enzymes, we can find cytochromes, necessary for the synthesis of chlorophyll; catalase, peroxidases and reductases of sulfates and nitrates, so it regulates the absorption of sulfur and nitrogen. In all these enzymatic systems, iron acts as an electron transporter.
The plant absorbs iron, by roots and leaves, as Fe+2 and Fe+.
Sulfur deficiencies are not common since sufficient amounts are present in the soil. But if this deficiency occurs, the plants suffer less growth and become stiff and brittle. Sulfur deficiency can be confused with a lack of nitrogen, both have widespread chlorosis in the leaves. Unlike nitrogen deficiency, the symptoms of its deficiency initially appear in young leaves, due to the immobility of sulfur