Importance of micronutrients in sustaining crop nutrition

The importance of micronutrients in sustainable crop production is usually linked to the focus on high yields and increased cropping intensity on existing arable lands for feeding the ever-increasing world population. However, micronutrient exports from cropping systems have often been neglected, while fertiliser strategies for high yields are largely based on NPK, particularly in developing countries. Land degradation such as organic matter loss and soil acidification has added another layer of complexity of managing micronutrients in cropping systems. Micronutrient fertilizer strategies must embrace changes in farming systems and land uses, including the shifts to no-till and water-saving rice production. In addition to effects of soil organic matter and soil acidification, micronutrient availability in the rooting zone is likely to be further influenced by erratic rainfall patterns and drought associated with climate change in the future. Solutions to these challenges will lie with well-designed agronomic measures such as regular replenishment of micronutrients through fertiliser inputs and crop residue management. Breeding traits of micronutrient efficiencies (including uptake and utilisation) into high yielding varieties of existing crops may be one of the long-term options for not only minimising crop failures, but enhancing crop quality such as micronutrient density in grain/seeds which are staple foods of populations who mainly consume plant-based food