Iron is one of the most widespread elements in the earth’s crust. It belongs to the group of trace elements, or elements that are needed in smaller quantities. Although the soil has significant amounts of iron, and plants need small amounts of this element, however the lack of iron is one of the most common problems in food plants. Lack of iron usually does not occur due to lack of this element in the soil, but because of his lack in plants. Iron is commonly found in the crystal structure of minerals and as such is not available to plants. Also, the solubility of oxides of trivalent iron is very low, so even though it has iron in the soil, it is unavailable to plants. The problem of availability of iron further highlights the carbonates and alkaline soils (pH over 7.5) in which the amount of soluble iron is minimal.
From all this it is concluded that iron deficiency is a result of his lack of plants and should be expected in soils that are alkaline reaction and are rich in carbonates, which are very common in our country. Lack of iron occurs in almost all cultures, and as more sensitive are: fruits, vines, legumes, soy, corn, tomatoes and sorghum.
Iron plays an important role in plants, primarily in the formation of chlorophyll. Therefore, in plants with iron deficiency have less amount of chlorophyll. Symptoms of iron deficiency chlorosis (yellowing of the leaves), which generally occurs at younger leaves (new growth). This chlorosis can be busy the whole plant or occur only at certain branches. The nerves of the leaves retain the green color. In case of a larger lack of iron, the leaves are almost white and quickly dying. Iron deficiency negatively affects the development of root and ultimately on yields, which are lower. Therefore, it is necessary to react with foliar application of iron or iron added by fertigation. Due to the fact that iron deficiency is a result of his unavailability should be used readily available forms, primarily iron chelated form. Recommended trash to apply irrigation water through the system and micro because chelate to the soil through the water needs of the plant for its growth and development, move and locate the root system, where it is released nutrient available in a form that easily and effectively adopted by the plant. The efficiency is reduced to strongly acidic and strongly basic soils, so in these soil types recommended foliar application.