Importance of micronutrients (Zinc) in crop production: A review

Abstract

Micro nutrients are designed to supply critically needed nutrients at the most responsive time during the growth cycle and to stimulate and optimize the assimilation and production process in the leaves. Micronutrients are the elements which are essential for the plant growth when roots are unable to absorb sufficient nutrients from soil due to high degree of fixation, losses from leaching, low soil temperature and lack of soil moisture. Zinc (Zn) is one of the eight essential micronutrients. It is needed by plants in small amounts, but yet crucial to plant development. In plants, zinc is a key constituent of many enzymes and proteins. It plays an important role in a wide range of processes, such as growth hormone production and internode elongation. Crop yield significantly increases with the use of micronutrients such as zinc (Zn), iron (Fe), boron (B), copper (Cu), manganese (Mn), etc. Zinc (Zn) has an important metabolically role in plants growth and development and is therefore called an essential trace element or a micronutrient. Zinc is uptake and transfers the form of Zn 2+ in plants and is an essential nutrient that has particular physiological functions in all living systems, such as the maintenance of structural and functional integrity of biological membranes and facilitation of protein synthesis and gene expression, enzymes structure, energy production and Krebs cycle; also has a positive impact on crops yield; therefore crops quantitative and qualitative yield is strongly dependent on zinc (Zn) in the soil. Calcareous soils with high intake of phosphorus (P) and soils with high pH are confronted with zinc deficiency. Zinc is an active element in biochemical processes and there is chemical and biological interaction between it and some other elements such as phosphorus, iron and nitrogen in plants. Phosphorus and copper have an antagonistic impact on zinc. The Food and Agriculture Organization (FAO) has determined that zinc is the most commonly deficient micronutrient in agricultural soils; almost 50% of agricultural soils are Zn deficient. Plants growing on potentially zinc-deficient soils have reduced productivity and contain very low concentrations of zinc in the edible parts (such as in cereal grains). Therefore, zinc deficiency represents a serious nutritional and health problem in human populations, especially in the developing world where cereal-based foods are the dominating source of diet. Hence, the review.