Effects of Micronutrient Fertilization on the Overall Quality of Crops

Abstract

Deficiency of micronutrients such as zinc (Zn) and iron (Fe) is a worldwide nutritional constraint in crop production particularly in growth, yield, and grain nutrient of crops, especially cereals such as wheat and rice in calcareous soils. On the other hand, Zn is an important nutrient for the growth and development of animals and humans and shortage in food causes severe damages economically due to malnutrition considerations. Micronutrient malnutrition in humans in developing countries is derived from deficiencies of these elements in staple food. Many approaches have been chosen to increase the Zn and Fe content in crops and ameliorate their malnutrition, including breeding, genetic engineering, and agronomic approaches. In this study, effects of agronomic biofortification components including different dose, proper stage of application, and effective method of micronutrient application are investigated on quantitative and qualitative yield of crops. The investigations of agronomy showed that micronutrient has an important role in the improvement of quantitative and qualitative crop yield. Hence, application of micronutrients such as Zn increased the grain yield due to its effect on the number of fertile spikelet per spike, number of grains per spike, and other agronomic traits. Also, this nutrient increased Zn and other micronutrient concentration in grain, grain protein, amino acid contents, and ascorbic acid content in grain but decreased phytic acid (PA) content and PA/Zn molar ratio in grain crops in most cases which increased bioavailability of micronutrients for human. In most cases, micronutrient application through foliar treatment performed better than other application methods. Studies indicated that application of micronutrients especially Zn and Fe led to increase in grain yield as well as positive aspects of seed quality and decrease in seeds’ negative qualities. Therefore, this approach (agronomic biofortification) can be used as appropriate short-term strategy, capable of improving quantitative and qualitative food security.