Role of Zinc Nutrition for Increasing Zinc Availability, Uptake, Yield, and Quality of Maize (Zea MaysL.) Grains: An Overview

Maize (Zea maysL.) is one of the most versatile crops and can be grown in diverse environmental conditions and has diversified uses as human food and animal feed. Maize grains cannot be considered only as a source of energy, as they provide significant amounts of protein as well. It is also recognized that maize grains have low micronutrient concentrations, particularly Zinc. Zn(2+)is an essential nutrient that has particular physiological functions in all living systems, such as the maintenance of structural and function of protein synthesis, gene expression, enzymes structure, energy production, krebs cycle, carbohydrate metabolism, photosynthesis, auxin metabolism, pollen formation, and resistance to infection by certain pathogen, also has a positive impact on crop yield. Therefore, crops qualitative and quantitative yield is strongly dependent on Zinc in the soil. Zinc deficiency is a problem, in almost all the crops and calcareous soils, intensively cropped soils, paddy soils and poorly drained soils, sodic soils and saline soils, peat soils, soils with high available phosphorus and silicon, sandy soils, highly weathered acid, and coarse textured soils. Phosphorus and copper have an antagonistic impact on Zinc. Zinc deficiency can affect plant by stunting its growth, decreasing crop maturity period, spikelet sterility, and inferior quality of harvest products. Maize is known as an indicator plant for the evaluation of Zn deficiency of a soil. The magnitude of zinc deficiency varies widely among soil types with reduction in crop yield and quality to the tune of 25-35% and in turn questions the nutritional security of human beings in developing countries like India, where cereals are the staple food. Despite high yield potential of maize, it gives low yields and low micronutrient content because of improper fertilizer management practices. Increasing productivity per unit area through proper management is one of the important strategies to increase the production of maize as well as micronutrient enrichment in grains. Understanding the distribution of zinc (Zn) in soils is important for effective and efficient management of the fertilizer resources.