What are foliar fertilizers – crystalline

Crystalline fertilizers are a group of loose fertilizers, adapted to the creation of water solutions and intended for foliar application, used to provide comprehensive nutrients to the fertilized plants.

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Currently, a wide range of this type of fertilizer is available on the Polish market. They successfully replace the more widely used liquid fertilizers, often based to a large extent on nitrogen. When introducing crystalline fertilizers, producers emphasized primarily:

• the possibility of obtaining higher concentrations of nutrients (in relation to liquid fertilizers),
• good stability of these products during storage,
• easiness to dissolve and mix.

What is the composition of crystalline fertilizers?

Virtually every producer determines the „original” composition of his fertilizer, which is usually a mixture of macro- and microelements with „unique” advantages. With this in mind, first of all, check the product label when choosing a specific fertilizer.

The micronutrients in this type of fertilizers are most often in the form of chelates (except boron and molybdenum), inorganic salts or oxides. In the case of chelate-based fertilizers, the composition should include:

• chelating agent,
• water-soluble form content,
• the content of the chelated form
• and the pH range that guarantees an acceptable value of the chelated form.

The content of the chelated form should not be less than 80%. The composition of chelate fertilizers may be adapted to the nutritional needs of a given plant or more universal. Chelated fertilizers are characterized by a good absorption of microelements. They often contain only one element in concentration. However, it should be taken into account that the effectiveness of chelates is determined by temperature and pH. The optimal range is 15 to 25 degrees Celsius, so they are not suitable for late fall or early spring treatments.

In the case of salt-based fertilizers, it is important to provide information on the content of micronutrients and their solubility in water. Inorganic salts of micronutrients (nitrates, sulphates, chlorides) dissolve well in water, but are less absorbed by the leaves. Consequently, they require the use of higher doses than chelates in order to achieve a similar effect. However, their action is effective at lower temperatures and is characterized by a higher concentration of ingredients.

The oxide form of the micronutrients is characterized by a high concentration with relatively low solubility. Hence, this group of micronutrients, due to the spread over time, is most often used to supplement the abundance of elements present in the deficiency in the soil.

DR GREEN foliar fertilizers – a modern solution

A completely new quality in the offer of crystalline fertilizers is the product of the Polish fertilizer brand Dr Green, established 10 years ago but already well-known to farmers. It combines all the factors determining effective and efficient feeding of plants.

This modern technology is based on micronutrient fertilizers – dedicated to specific types of crops – and universal fertilizers: macronutrients. The possibility of using them in various combinations, depending on the current needs and conditions (application date, weather conditions, course of vegetation) has become an effective method of increasing the quality of crops and crop efficiency.

The innovative formula and the pH stabilizer included in the composition combine with such features as:

• Innovative formula and the highest content of ingredients and absorbtion,
• excellent solubility and miscibility with most plant protection products,
• effectiveness in relatively low temperatures,
• the content of amino acids and vitamins that have a stimulating and anti-stress function.

It can therefore be said that this fertilizer combines and at the same time surpasses all the advantages of its predecessors.

Chelated vs Non-Chelated Nutrients: Choosing the Right Form for Crops

What are Chelated Nutrients?

In agronomy, chelation refers to the process of binding a nutrient ion with a protective molecule, known as a chelating agent.
This bond isolates the nutrient from unwanted chemical reactions, making it more stable and more available for plants compared to non-chelated forms.

A chelated nutrient can be imagined as a micronutrient "wrapped" in a protective shell, preventing it from becoming unavailable in the soil or solution.

Which Nutrients Are Chelated?

Chelation is primarily applied to micronutrients, since these elements are particularly sensitive to precipitation and pH fluctuations:

• Iron (Fe)
• Zinc (Zn)
• Manganese (Mn)
• Cobalt (Co)
• Copper (Cu)
• Nickel (Ni)

In some cases, other elements like Boron (B), Molybdenum (Mo), or even Calcium (Ca) are sold in complexed or partially chelated forms. However, these are less common and not considered classical chelation compared to micronutrients like Fe, Zn, Mn, or Cu.

For more Microelement Chelated Fertilizerinformation, please contact us. We will provide professional answers.

Advantages of Chelated Nutrients

1. Wider Effective pH Range

• Non-chelated nutrients are usually stable and available only up to pH ≈ 6.1.
• Chelated forms remain effective in much higher pH values — in some cases up to pH ≈ 10–12, depending on the chelating agent.

2. Better Plant Uptake

Chelated micronutrients are absorbed more efficiently because the chelating agent prevents them from binding with soil particles or forming insoluble compounds.

3. Stability in Nutrient Solutions

When preparing a nutrient solution for fertigation:

• Iron (Fe²⁺) can oxidize to Fe³⁺ at higher pH, making it unavailable.
• Micronutrients can react with other fertilizers, creating insoluble precipitates.
  Chelated forms remain soluble and available, even in challenging water conditions.

Simply put: chelated nutrients stay available longer and are absorbed better.

Common Chelating Agents

Below is a quick comparison table of the most frequently used chelating agents in agriculture:

ChelateEffective pH RangeCostEnvironmental ProfileTypical ApplicationNotesEDTAup to 6.5Medium❌ Not eco-friendlyFoliar sprays, open-field fertigationCommonly used for Fe, Zn, Mn, CuIDHAup to 6.4Medium⚠️ Moderately eco-friendlyFoliar sprays (short-term), hydroponicsFully biodegradable, quick releaseGLDAup to 6.5Medium✅ Eco-friendly (biodegradable)Foliar sprays, fertigation, sensitive systemsSustainable alternative to EDTADTPAup to 7.5Medium–High⚠️ Moderately eco-friendlyFertigation (soilless hydroponics, greenhouses)Stronger stability than EDTAEDDHAup to 10Very High❌ Not eco-friendlyOpen-field fertigation, soil injection (calcareous soils)Excellent for alkaline soilsHBEDup to 12Very High❌ Not eco-friendlySoil injection, soilless systems, calcareous soilsExtremely stable, long-lasting Fe source

• EDTA – Affordable and widely used, but ineffective in alkaline soils.
• IDHA – Fully biodegradable, best for short-term Fe correction in hydroponics.
• GLDA – Strong eco-profile, designed as a sustainable alternative to EDTA.
• DTPA – Reliable in greenhouses and soilless systems, a balance between cost and stability.
• EDDHA – The standard for high-pH soils, though costly and not eco-friendly.
• HBED – Exceptional stability at extreme pH, but rarely used due to price.

Chelated vs Non-Chelated in Practice

The key difference between chelated and non-chelated nutrients is their stability: chelated forms remain soluble and plant-available across a wider pH range, while non-chelated forms can quickly precipitate or bind to soil particles. When choosing between chelated and non-chelated nutrients, growers should consider:

• Soil pH – Acidic soils (< 6.0) allow many nutrients to remain soluble even without chelation.
• Water alkalinity – High alkalinity requires stronger chelates like EDDHA or HBED to keep iron soluble.
• Economic factors – Chelates are more expensive but prevent deficiencies that can reduce yield.

When Non-Chelated Nutrients Can Be Used

Despite the advantages of chelated nutrients, non-chelated forms can still be a valid and effective alternative under the right pH and management conditions. While chelated forms provide clear advantages, non-chelated nutrients are still widely sold and can be appropriate in certain scenarios:

1. Acidic conditions – If the water or soil pH is naturally low, many micronutrients remain soluble without chelation.
2. Cost-saving strategies – Non-chelated forms are cheaper. By slightly acidifying irrigation water using common acids (like phosphoric or nitric acid), the pH drops and non-chelated nutrients become more available.
3. Short-term applications – For fast, one-time fertilization in controlled conditions, non-chelated nutrients can perform adequately.

With careful pH management, growers can reduce costs on chelated fertilizers without compromising yield.

Chelates in Hydroponics

In hydroponic systems, nutrient solutions are mixed with precise control over pH and EC.
This makes chelated nutrients particularly important:

• Non-chelated salts can work if the pH is carefully maintained at ~5.5–6.1.
• Iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) are highly prone to precipitation or oxidation, so they are usually supplied as chelates.
• Fe-DTPA and Fe-EDDHA are the most common choices for hydroponics due to their stability.
• GLDA and IDHA are sustainable alternatives, especially for growers seeking biodegradable options.

In practice: hydroponic growers often combine non-chelated macronutrients (like Ca, Mg, K) with chelated micronutrients, ensuring maximum solubility and long-term stability of the solution.

Conclusion

Chelated nutrients represent a more stable, more efficient, and more plant-available solution compared to their non-chelated counterparts.

However, non-chelated nutrients can be cost-effective when used in the right context, particularly in acidic conditions or with water pH management.

When choosing between chelated and non-chelated nutrients, growers should consider:

• The pH of their soil or water
• Which micronutrients are most critical
• How to balance cost with sustainability

Investing in the right chelate can mean the difference between deficiency symptoms and a healthy, high-yielding crop — but smart use of non-chelated forms can also save money without sacrificing yield.

Ensure Plants Absorb Every Nutrient

Use Growing Farm to match nutrients to growth stages, calculate precise fertilizer doses, and optimize chelation for better yields.

If you want to learn more, please visit our website Gypsum Retarders.