Micronutrients in fertilizers occupy a central position in modern crop nutrition systems, as no successful fertilization program is complete without a precise understanding of their role and mechanisms of action. Although plants require these elements in minute quantities, their absence or deficiency leads to acute physiological disorders that directly affect crop quality and yield.
With growing global demand for Micronutrient fertilizers, whose market value exceeded $5.9 billion in 2025 and is projected to reach $8.25 billion by 2030, these elements have become core concerns for manufacturers, exporters, and crop nutrition specialists alike.
In this guide, we address micronutrients in fertilizers from a comprehensive perspective that combines scientific foundations with practical industrial application, with particular focus on the forms used in compound granular fertilizers and the quality standards sought by international buyers.
Table of Contents
What Are Micronutrients in Fertilizers and Why Do They Matter?
micronutrients in fertilizers
The Difference Between Macronutrients and Micronutrients
The essential nutrients required by plants are divided into two main groups. The first is macronutrients, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur, which plants need in relatively large quantities to build vegetative mass and support overall growth.
The second group is micronutrients, also known as trace elements, which include zinc, iron, boron, manganese, copper, molybdenum, chlorine, and nickel. Plants require these in extremely small amounts, sometimes no more than a few parts per million (ppm) of dry matter weight.
However, this quantitative difference does not imply lesser importance. Both groups are essential for healthy plant growth, and deficiency in any one of them causes clear physiological dysfunction in the plant.
Why Can’t Micronutrients Be Dispensed With Despite Their Small Quantities?
Micronutrients perform vital functions that no other element can replace. They are involved in activating dozens of enzymes essential for photosynthesis, energy generation, and resistance to environmental stress. They also play a pivotal role in chlorophyll formation, atmospheric nitrogen fixation, flowering and fertilization processes, and seed development. In short, they are the keys that operate the plant’s biological machinery, without them, fundamental processes come to a halt even when macronutrients are abundantly available.
Liebig’s Law and Its Relationship to Micronutrient Balance in Crop Nutrition
Liebig’s Law of the Minimum illustrates this truth eloquently: plant growth and productivity are not determined by the most abundant element, but by the scarcest one. This means that supplying a crop with generous quantities of nitrogen and phosphorus will not compensate for a zinc or boron deficiency, and in some cases may actually aggravate deficiency symptoms. This is precisely why a balanced fertilization program that encompasses both macro and micronutrients is indispensable.
The Most Important Micronutrients in Fertilizers and Their Physiological Role
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Zinc: The Most Widely Used Element in Granular Fertilizers
Zinc holds the leading position among micronutrients in terms of global demand, accounting for 28.5% of the micronutrient fertilizer market share in 2024. This is largely due to the widespread deficiency of zinc in alkaline and calcareous soils, particularly across the Middle East and South Asia.
Functionally, zinc participates in activating more than 300 enzymes and directly influences the formation of growth auxins, internode elongation, and the quality of grains and fruits. Its deficiency manifests clearly as plant stunting, shortened internodal spacing, and whitening of leaf tips.
Boron: Its Critical Role in Flowering and Fruit Set
Boron is the fastest-growing segment in the micronutrient fertilizer market, expanding at 7.5% annually through 2030, driven by the expansion of oilseed and fruit cultivation in water-scarce irrigated zones. Boron controls sugar transport across cell membranes and is essential for cell wall formation, pollen grain development, and the fertilization process. Its deficiency halts fruit set and converts growing tips into sterile floral clusters, causing significant crop losses.
Iron: The Foundation of Chlorophyll Formation and Overcoming the Alkaline Soil Problem
Iron is closely linked to photosynthesis as a fundamental component of chlorophyll synthesis and the electron transport system. Its central challenge is that alkaline soils (pH above 7) fix iron into insoluble forms that plants cannot absorb, causing deficiency symptoms (chlorosis) to appear even when iron is present in the soil. This is why selecting the appropriate chemical form (chelated or oxide-based) is critically important when formulating iron fertilizers for alkaline soil regions.
Manganese, Copper, and Molybdenum: Other Micronutrients of Equal Importance
Manganese participates in multiple enzymatic processes and in splitting water molecules during photosynthesis. Its deficiency is common in sandy soils with elevated pH. Copper is involved in activating oxidation-reduction enzymes and accounted for 25.5% of market share in 2024 due to its widespread use. Molybdenum, despite being required in negligible amounts, is indispensable for atmospheric nitrogen fixation and the function of nitrate reductase enzyme, making it a cornerstone of nitrogen fertilizer use efficiency.
see also Organic Fertilizer Export Guide: Quality Standards and Global Market Opportunities
Forms of Micronutrients in Fertilizers: Which Should You Choose?
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Chelated Micronutrients: EDTA vs. EDDHA, Which Is Better?
Chelated fertilizers represent the highest-efficiency technology for making micronutrients available to plants. In these formulations, elements are bound by organic molecules (chelating agents) that protect them from reacting with soil components and becoming fixed.
The two most prominent types are EDTA and EDDHA. EDTA is effective in pH ranges between 4 and 7 and is used for foliar application and fertigation, while EDDHA outperforms it in strongly alkaline soils (pH 8–9) and is the optimal choice for calcareous soil regions such as the Gulf and North Africa. Chelated fertilizers carry a higher cost, but their use efficiency clearly compensates for this in challenging environments.
Sulphate-Based Micronutrient Fertilizers: Economic Application and Its Limits
Sulphate-based fertilizers such as zinc sulfate and copper sulfate are characterized by high water solubility and competitive pricing, making them the most widely used in conventional fertilization programs. However, their limitations emerge in soils with elevated pH, where the elements rapidly convert to unavailable forms.
They may also cause clogging in drip irrigation lines when improperly mixed. These fertilizers are best suited for light to moderately acidic soils and perform well as soil applications at the start of the season.
Micronutrients in Compound Granular Fertilizers
Advanced granulation technology allows micronutrients to be incorporated within the fertilizer granule with precise and uniform distribution, and this is what distinguishes compound granular fertilizers from simple mechanical blends.
In each granule, macro and micronutrients are distributed at defined ratios, ensuring that every part of the soil receives its balanced share of nutrients with each application. This simplifies field fertilization operations, reduces the number of applications, and raises use efficiency, which is exactly what industrial buyers managing large-scale agricultural operations are looking for.
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Micronutrient Deficiency in Soil: Causes, Symptoms, and Diagnostic Methods
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Soil Conditions That Restrict Micronutrient Availability
Several factors limit micronutrient availability even when they are present in the soil. The most prominent is a pH above 7, which converts many elements into insoluble, non-absorbable forms. High calcium carbonate content (calcareous soils) similarly restricts the mobility of zinc, iron, and manganese.
Excessive phosphorus applications reduce zinc availability through what is known as phosphorus-zinc antagonism. Add to this low organic matter content and the high temperatures of the Middle East region, which accelerate the oxidation of certain elements.
Micronutrient Deficiency Symptoms in Plants: A Visual Guide for Rapid Diagnosis
Deficiency symptoms vary according to the nature of each element and its mobility within the plant. Zinc deficiency begins in young leaves as pale bands on either side of the midrib, accompanied by noticeable stunting.
Iron deficiency produces interveinal chlorosis in young leaves while the veins remain green. Boron deficiency leads to destruction and clustering of growing tips into sterile floral formations. Manganese deficiency, by contrast, appears on middle-aged leaves as interveinal yellowing similar in appearance to iron deficiency. This precise differentiation is essential for making rapid corrective decisions.
The Role of Soil Analysis in Determining Micronutrient Fertilizer Requirements
Visual diagnosis alone is insufficient. Pre-season soil analysis is the most accurate scientific tool for identifying deficient elements and designing a customized fertilization program. The DTPA extraction test is recommended for zinc, iron, manganese, and copper in high-pH soils, while hot water extraction tests give accurate results for boron.
For fertilizer manufacturing specialists, this data forms the basis for precise formulation of compounds tailored to the requirements of specific target markets.
Methods of Micronutrient Application: Soil, Foliar, and Fertigation
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When Is Soil Application Through Granular Fertilizers Preferred?
Soil application is the most sustainable approach for permanently correcting micronutrient deficiencies, particularly when the deficiency is structural and tied to the nature of the soil itself. Compound granular fertilizers containing micronutrients offer a clear competitive advantage here, as they ensure uniform distribution in the root zone from the very first moment of germination.
This method accounts for 88.3% of total global micronutrient fertilizer usage, a figure that reflects the confidence of farmers and large-scale agricultural operators in its effectiveness.
Foliar Application of Micronutrients: Benefits and Limitations
Foliar spraying enables rapid correction of acute deficiency symptoms, especially for elements like iron, manganese, and zinc whose movement is restricted by alkaline soils. It is typically used during critical growth stages such as flowering, fruit set, and fruit development. However, this method remains curative rather than preventive, and is influenced by external factors such as temperature, light intensity, and spray droplet size. Its effect is also temporary and does not address the underlying soil problem.
Fertigation and How It Enhances Micronutrient Efficiency
Fertigation, the application of fertilizers through irrigation water, is the fastest-growing application method in this sector, expanding at a 6.9% CAGR through 2030. It enables delivery of micronutrients directly to the root zone at controlled concentrations and at precisely the right time.
This method requires the use of highly soluble fertilizers such as chelated forms or pure sulfates, along with adherence to chemical compatibility rules when mixing, to prevent element precipitation in irrigation lines.
International Quality Standards for Micronutrient Fertilizers
micronutrients in fertilizers
International Specifications and European Regulations on Micronutrient Thresholds
The European Union set a cadmium limit for phosphate fertilizers at 1.5 mg/kg P₂O₅ in 2024, prompting manufacturers to shift from low-grade sulfates toward purified chelated forms. At the content level, most international quality standards require disclosure of total element content, water-soluble fraction, and chelated fraction where applicable.
This level of disclosure detail is a fundamental standard for professional manufacturers and firmly establishes their credibility with international buyers.
What Does the International Buyer Look for in Micronutrient Fertilizers?
The international industrial buyer focuses on several criteria when evaluating micronutrient fertilizers. Chief among these are precision in granule size uniformity and element distribution, clarity of chemical analysis certificates (COA), and compliance with recognized quality standards such as the European EN 13650. In addition, buyers place growing importance on product stability during storage and shipping, and on the availability of field efficacy data that demonstrates the formulation’s performance under conditions similar to their own geographic region.
Conclusion
In modern agriculture, micronutrients are no longer optional; they are a fundamental component of any balanced fertilization program aimed at achieving high productivity and consistent crop quality. As soil challenges increase, fertility declines, and global market requirements become more demanding, understanding the role of micronutrients and selecting the right fertilizer forms has become essential for both farmers and manufacturers.
Combining scientific soil analysis, advanced fertilizer manufacturing technologies, and the correct application methods ensures maximum nutrient use efficiency while reducing waste and costs. Ultimately, balanced fertilization that integrates both macro and micronutrients remains the key to sustainable agriculture and high-quality crop production that meets future demands.
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Frequently Asked Questions About Micronutrients in Fertilizers
What Is the Difference Between Micronutrients and Macronutrients in Fertilizers?
Macronutrients such as nitrogen, phosphorus, and potassium are required by plants in large quantities to build vegetative mass. Micronutrients such as zinc, iron, and boron are needed in very small amounts, but are no less important, they govern vital enzymatic processes and directly affect crop quality and quantity when absent.
Why Do Micronutrient Deficiency Symptoms Appear Even When Full Fertilization Has Been Applied?
The most common reason is elevated soil pH, which converts elements into forms that cannot be absorbed by plant roots. Additionally, excess phosphorus can interfere with zinc uptake. This is why soil testing is always recommended, along with selecting the appropriate fertilizer form, chelated or sulphate-based, according to the specific nature of each soil.
What Is the Difference Between Chelated and Sulphate-Based Micronutrient Fertilizers?
In chelated fertilizers, elements are bound by organic molecules that protect them from soil fixation, making them more effective in alkaline and calcareous soils. Sulphate-based fertilizers are highly soluble and economical but less stable in the soil. The choice depends on soil pH, crop type, and the application method being used.
Can Micronutrients Be Incorporated Into Compound Granular Fertilizers?
Yes, and this is one of the most significant advantages of granulation technology. It allows uniform distribution of micronutrients within each granule, simplifying fertilization operations, reducing the number of applications, and ensuring that every part of the soil receives its balanced share of trace nutrients, thereby raising use efficiency and minimizing waste.
Which Micronutrients Are Most Commonly Deficient in Middle Eastern Soils?
Zinc is by far the most prevalent deficiency, due to the widespread occurrence of calcareous and limestone soils with high pH. Iron and boron follow closely. High solar radiation and elevated temperatures in the region further compound the problem by accelerating the oxidation of certain elements. Chelated zinc and iron fertilizers are therefore considered the most suitable solutions for this agricultural environment.