Agriculture · Selection guide

Agricultural chelating agent selection guide

Identity

Agricultural

Chelating Agent

Selection Guide

Criteria EDTA GLDA MGDA DTPA

Best For

Best Metals

Preferred Soil pH

Recommended

Formulation pH

Preferred Metal

Salts

Chelating Strength

Biodegradability

Typical Chelate:

Metal Ratio

Formulation

Advantages

When to Choose

Typical

Applications

General-purpose

Zn, Mn, Cu and Fe micronutrients

Zn, Mn, Cu, Fe (acidic to neutral pH)

Acidic to neutral (<6.5)

3.5–7.0

High

Sulfates, nitrates,

Typical properties and specifications

chlorides

Poor

1.00–1.05 : 1

Lowest cost, proven performance, high metal loading

Cost-sensitive commodity fertilizers and standard

Zn/Mn/Cu products

Foliar nutrients, fertigation, liquid micronutrients, NPK blends

Sustainable micronutrients, mixedmetal fertilizers, biologicals, humic/seaweed products

Zn, Mn, Cu, mixed micronutrients

Acidic to neutral (<7.0)

2.5–7.0

Moderate

Sulfates (preferred), nitrates, chlorides

Excellent (readily biodegradable)

1.10–1.50 : 1

Excellent compatibility with

Applications and benefits

biologicals, humics, seaweed extracts, hard water, and sustainable formulations

Premium sustainable fertilizers, biodegradable products, multimicronutrient blends

Premium foliar fertilizers, biological fertilizers, biostimulants, regenerative agriculture

Calcium- & magnesium -rich formulations, sustainable fertilizers

Ca, Mg, Zn, Mn

Acidic to neutral (<7.0)

3.5–8.0

Moderate-High

Sulfates, nitrates

Excellent (readily biodegradable)

1.05–1.20 : 1

Excellent calcium tolerance, broad compatibility, sustainable

Formulations containing calcium or

Use levels, packaging, and storage

magnesium or requiring biodegradable chelation

Specialty liquid fertilizers, calcium/ magnesium products, sustainable nutrition

Iron fertilizers, iron chlorosis correction, alkaline soils

Fe, Cu, Zn

Neutral to alkaline (6.5–8.5+)

4.0–8.5

Very High

Sulfates, nitrates

Poor

1.00–1.05 : 1

Highest iron stability, longest shelf life for

Fe products, best high-pH performance

Iron fertilizers for alkaline/calcareous soils or where maximum

Fe stability is required

Iron chelates, fertigation, turf, ornamentals, orchards, vineyards, chlorosis correction