What Is EDTA-CuNa2? Copper Chelate Guide for Agriculture

Written by: ALEN, Chemical Engineer, MOSINTER | 15 years in vitamin manufacturing and pharmaceutical APIs
 

Two weeks ago, an agronomist from Brazil reached out with a problem that sounded all too familiar: his soybean fields were showing classic copper deficiency symptoms-pale new growth, weak stems, delayed flowering-despite multiple applications of copper sulfate. The issue? High soil pH was locking up the copper before plants could absorb it. This is exactly where chelated copper, specifically EDTA-CuNa2 (CAS 14025-15-1), makes all the difference.

EDTA-CuNa2, also known as Copper Disodium EDTA or Ethylenediaminetetraacetic Acid Copper Disodium Salt, is a water-soluble chelated micronutrient fertilizer that delivers copper to plants in a highly bioavailable form. Unlike conventional copper sulfate, EDTA chelation protects copper ions from reacting with soil components, ensuring 3-5x better absorption efficiency across a pH range of 4-9. The molecular formula is C10H12CuN2Na2O8, with EC Number 237-864-5 according to the European Chemicals Agency (ECHA).

In This Guide:

1. Why Copper Chelation Matters for Crop Health

2. EDTA-CuNa2 Technical Specifications

3. Application Methods and Dosage Guidelines

4. EDTA-CuNa2 vs. Copper Sulfate: Performance Comparison

5. How to Select a Reliable Supplier

6. Frequently Asked Questions

1. Why Does Copper Chelation Matter for Crop Health?

Here's what most fertilizer suppliers won't tell you: applying raw copper sulfate to alkaline soils is essentially throwing money away. In soils with pH above 7, copper rapidly converts to insoluble hydroxides and carbonates that plants simply cannot access.

Chelated copper solves this problem by forming a stable, water-soluble complex where the copper ion is protected within an organic molecular 'cage.' According to research from the University of Florida IFAS Extension, chelated micronutrients remain plant-available across a much wider pH range than inorganic salts. The EDTA ligand specifically maintains copper availability from pH 4 up to pH 9, covering virtually all agricultural soil conditions.

 

Copper serves as a critical enzyme activator in plants. It's essential for photosynthesis, lignin synthesis (which strengthens cell walls), and pollen formation. When copper is deficient, you'll notice symptoms appearing first on new growth-that's because copper is immobile in the plant and cannot be redistributed from older tissues. Typical signs include chlorosis of young leaves, wilting despite adequate water, and what agronomists call "die-back" at shoot tips.

Table 1: Copper Deficiency Symptoms by Crop Type

2. EDTA-CuNa2 Technical Specifications

When evaluating EDTA-CuNa2 for procurement, understanding the key specifications helps you avoid quality issues. I've seen batches from questionable sources that fell short on copper content or contained excessive moisture-problems that directly affect field performance.

High-quality EDTA-CuNa2 should contain 14-15% chelated copper content, appear as a uniform blue crystalline powder, and dissolve completely in water without residue. The compound's stability is another critical factor. Per PubChem database records, the copper-EDTA complex remains stable under normal storage conditions and across typical agricultural pH ranges.

Table 2: EDTA-CuNa2 Product Specifications

3. Application Methods and Dosage Guidelines

One of the most common mistakes I see from first-time users is over-application. Copper, while essential, can become toxic to plants at excessive levels. The beauty of EDTA-CuNa2 lies in its efficiency-you need far less product compared to inorganic copper sources.

 

For foliar application, dilute EDTA-CuNa2 at a ratio of 1:2000 to 1:3000 (approximately 0.3-0.5 g per liter of water). Apply 2-3 times during the growing season with 10-15 day intervals between applications. Early morning or late afternoon spraying minimizes evaporation and maximizes leaf absorption. Avoid application during peak sunlight hours or when rain is expected within 6 hours.

For soil application through fertigation, drip irrigation, or root drenching, use 500-1000 grams per acre (1.2-2.5 kg/hectare). This method works particularly well in sandy or organic-rich soils where copper retention is naturally low.

Table 3: Recommended Application Rates by Method

4. EDTA-CuNa2 vs. Copper Sulfate: Which Performs Better?

Copper sulfate (CuSO4) has been the traditional copper source for decades. It's inexpensive and widely available. So why consider paying more for chelated copper? The answer lies in what happens after application.

In side-by-side trials, EDTA-chelated copper consistently delivers 3-5 times greater plant uptake efficiency compared to copper sulfate, particularly in calcareous or high-pH soils. This means you use less product to achieve the same result-and avoid the risk of copper accumulation in soils that can occur with repeated sulfate applications.

 

Table 4: EDTA-CuNa2 vs. Copper Sulfate Performance

5. How to Select a Reliable EDTA-CuNa2 Supplier

After 15 years in this industry, I've learned that price alone tells you very little about product quality. A batch that costs 20% less but contains 12% copper instead of the specified 15% ends up costing you more per unit of actual copper delivered. Here's what to look for:

Request a Certificate of Analysis (COA) for every batch. Reputable suppliers provide this automatically. The COA should confirm copper content, pH, heavy metal limits (particularly lead and cadmium), and water solubility. If a supplier hesitates to provide batch-specific documentation, that's a red flag.

Verify manufacturing certifications. ISO 9001 quality management certification indicates systematic quality control. For agricultural applications, look for suppliers who can provide REACH compliance documentation for European markets or EPA registration for US markets.

Assess production capacity and delivery reliability. Nothing derails a growing season like a supplier who can't meet delivery deadlines. MOSINTER maintains an annual production capacity of 50,000 metric tons across our chelating agent product line, with standard lead times of 7 days for most orders.

 

6. Frequently Asked Questions

Is EDTA-CuNa2 safe for organic farming?

EDTA is a synthetic chelating agent, so EDTA-CuNa2 is not OMRI-listed for certified organic production. For organic operations, copper sulfate (with restrictions) or approved organic copper sources should be used instead. However, EDTA-CuNa2 is excellent for conventional agriculture, hydroponic systems, and integrated pest management (IPM) programs.

Can I mix EDTA-CuNa2 with other fertilizers and pesticides?

Yes, EDTA chelation provides excellent tank mix compatibility with most common fertilizers and pesticides. Always perform a jar test before large-scale mixing. Avoid combining with highly alkaline products (pH >10) or high-calcium solutions, as these can destabilize the chelate complex.

Is copper chelate toxic to livestock?

Copper is highly toxic to sheep, even at moderate levels. Do not apply EDTA-CuNa2 in areas where sheep graze, and prevent runoff into sheep pastures. Cattle and other livestock have higher copper tolerance but should not have direct access to treated areas until the product has been watered in and dried.

How long does EDTA-CuNa2 remain effective in soil?

The chelated form maintains copper availability for 2-4 weeks longer than inorganic copper sources under typical soil conditions. Effectiveness duration depends on soil type, moisture levels, and microbial activity. In sandy soils, more frequent applications may be necessary.

What is the shelf life of EDTA-CuNa2?

When stored properly in a cool, dry place with the container tightly sealed, EDTA-CuNa2 maintains stability for at least 2 years. Exposure to moisture or extreme temperatures can cause caking and reduce solubility. Always check product appearance before use-a uniform blue crystalline powder indicates good quality.

Conclusion

EDTA-CuNa2 represents the most efficient method for delivering bioavailable copper to crops, especially in challenging soil conditions where conventional copper sulfate fails. With 21 years of manufacturing experience and production capacity exceeding 50,000 tons annually, MOSINTER is positioned to support your agricultural copper requirements with consistent quality and reliable supply.

Ready to optimize your copper nutrition program? Contact MOSINTER today for product specifications, pricing, and technical support.

WhatsApp: +8618989305995

Email: info1@mosinterchem.com

Product Page: EDTA-CuNa2 CAS 14025-15-1

Last Updated: January 2026