Response of Plants Grown on Sandy Soils to Micronutrient-Ores Application

Abstract

To grow healthy, plants which give high yield and quality, the crop (plant) needs micronutrients to feed on. Although micronutrients are needed in very small amounts, compared with macronutrients, the importance of micronutrients is not less than of the other macronutrients. Deficiency in micronutrients leads to lower yields, lower quality

and in severe cases no yield at all as it is in the case ofhighly calcareous and sandy soils. New reclaimed sandy and calcareous soils have low fertility and low content of macro and micronutrients to the degree that renders them limiting factors of productivity. This situation prompted Egyptian research workers to study the requirements of various crops for micronutrients, their content in various types of soils and the extent of their availability to plants. The suspended matter was considered a continuous source for supplying the soils of Egypt with both micronutrients and some macronutrients before High Dam construction. Nowadays, the recently sandy and calcareous cultivated soils of Egypt contain low total and available micronutrients levels compared to alluvial soils. The provision of the optimum nutritional-requirements to crops is not linked only to the provision of the requirements from every individual nutrient, but also to the balance among different nutrients. Therefore, the study of micronutrients should be conducted within the frame of an integrated and balanced crop nutrition. Micronutrients sources vary considerably in their state, chemical reactivity, costs per unit of each micronutrient element, and its availability to plants. The main four classes ofmicronutrients sources are: inorganic products, synthetic chelates, organic complexes and fritted