Though the requirement of micronutrients is in trace quantities, these are considered as very essential for the plant’s metabolic growth and development. The demand for micronutrients has been witnessed across all the geographic regions as the soil composition can be deficient in one or more of the micronutrients. In addition to these, there is a large reduction and degradation of available land resources for agriculture. The fertility of the soil gets degraded due to soil erosion, salinization, intensive usage of fertilizers, and excessive liming to neutralize acidic soils. The prevalence of restraints such as lack of awareness among the farmers is upholding the demand for micronutrient market. Due to globalization, the export quality of agri-commodities has become standardized, which emphasizes on the importance of the maintenance of the crop’s condition. The dosage of each micronutrient varies with each crop, based on its requirement and intake capacity. The dosage also depends on the soil characteristics as alkaline soils may not allow soil micronutrient absorption.
Historically, the introduction and increased use of macronutrient fertilizers was an instrumental part of the Green Revolution (between the 1940s and the late 1960s) which increased the productivity across the Asia-Pacific region. Significant attention has been paid to macronutrient fertilizers, but this has been somewhat less true for the micronutrient fertilizers. Intensive cropping and enhanced productivity in marginal soils have caused greater depletion of native soil micronutrients, which in turn has resulted in multi-nutrient deficiencies and higher responses to micronutrient fertilization. According to the International Fertilizer Association (IFA), 50% of cereal soils are deficient in zinc and 30% of cultivated soils are deficient in iron, globally. In many agricultural farms across the world, the amount of micronutrients supplied to crops is low when compared to their uptake. Thus, there is an urgent need to concentrate on achieving balance with regard to micronutrients.
Most irrigated crops (especially rice and wheat crops occupy vast area in Asia-Pacific) are experiencing declining response trends because of several factors including application of unbalanced dosages of fertilizers, micronutrient deficiencies, lack of proper management, and declining soil fertility. Therefore, nations across the world are taking steps to overcome from the inefficiencies in the crop production by increasing the efficiency of farm inputs applied. For instance, the Indian government had established a policy in 2008 for encouraging the production and availability of ‘Fortified and Coated Fertilizers’. The process of fortification involves enriching a regular fertilizer product with micronutrients such zinc and boron.
Agricultural research organizations are educating farmers across the various nations to use micronutrients to increase the efficiency of macronutrients (N, P, and K). This is because, the loss of nitrate is higher due to other limiting factors such as deficiencies of secondary or micronutrients. China and India are the main users of micronutrients in the Asia-Pacific region. These countries employ intensive cropping techniques with limited soil replenishment practices. According to the FAO, the Asian soils are enormously deficient in zinc and selenium content. In order to provide wholesome plant nutrition to maintain export quality standards, the Asia-Pacific region has become dependent on micronutrient application. Even then, the farmers lack the awareness to follow the critical application doses whose excessive usage can cause toxicity within the plants.
Micronutrients such as zinc, manganese, boron, and iron are often supplemented to the main crops in North America. The consumption of micronutrients is driven by the awareness regarding the production of better crop quality. Adoption of cropping pattern, soil testing, and precision agriculture has driven the U.S. and Canadian markets. Though traditional agricultural practices are still followed in Mexico, the farmers are encouraged to espouse the use of micronutrients such as zinc and boron for a sustainable and high-quality crop produce.
Due to reduced availability of agricultural land and increased land degradation, the European nations have to vertically integrate their agricultural productivity with the application of micronutrients. The most commonly deficient micronutrient observed in the European soils is boron.
The acidic and infertile Latin American soil requires the application of liming and fertilizers. However, these two agricultural practices, if used immoderately, could reduce the plant’s ability to absorb micronutrients. These soils are reported to be deficient in zinc, copper, boron, manganese, and iron. The African countries are catching up very slowly with the global market because of lack of awareness and inadequate agri-development programs. The highly iron-deficient African regions and intensive croppers of Latin America have understood the necessity of micronutrients to increase crop yield and quality.
Looking ahead, more policy reforms are needed to promote appropriate application of micronutrients to increase the efficiency of macronutrients and also to avoid nutrient deficiencies in the soil. Micro-enriched fertilization has to be prioritized to fight malnutrition in soils, livestock, and people. The importance of addressing all micronutrients in soil as well as in food items has to be given due recognition in the upcoming years to save the people who are suffering from nutritional deficiencies. Application of large amounts of fertilizers harms the environment.
