Achieving stable micronutrient formulations in demanding conditions

Hard water, electrolyte stress and fluctuating pH can destabilise liquid micronutrient fertilisers, leading to precipitation, crystallisation and reduced formulation reliability. At the same time, formulators are under pressure to increase micronutrient concentration while maintaining fully soluble and compatible systems. These formulations must also deliver strong agronomic performance to succeed.

KEY CHALLENGES

  • Stabilising micronutrients across wide pH ranges

  • Maximising micronutrient concentration

  • Improving compatibility in hard water and high salt concentrations

  • Effectively and safely delivering micronutrients for superior uptake and yield
how we solve it

Formulating better liquid micronutrients 

Our complexing agents help formulators develop stable, high-performance liquid micronutrient fertilisers for demanding agricultural conditions.

Maintain Stability Across Wide pH Conditions

Lignosulfonates help keep micronutrients soluble under varying pH conditions, supporting more stable liquid fertilizer formulations.

Enable Higher Micronutrient Concentration

By stabilizing micronutrients in solution, lignosulfonates help support higher nutrient loading in fully soluble liquid fertilizers.

Superior micronutrient uptake and yield

Our complexing agents help reduce the risk of precipitation and crystallisation even in hard water and high electrolyte conditions.

TRIAL DATA

Maintain stability in hard water and a wide pH range

To simulate calcareous soil and hard water tank-mix conditions, iron and zinc solutions (2 mM) were prepared at different pH values in the presence of 100 mM CaCl₂. Under these conditions, lignosulfonate-based formulations maintained a higher percentage of iron and zinc in solution than gluconate- and amino acid-based formulations.

This enables formulators to maximise micronutrient loading without compromising stability, even under challenging conditions. The stability provided by Marasperse® AG can support improved agronomic performance.

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% Soluble micronutrient remaining in solution after 3 days storage. Data digitised and reconstructed from: J. J. Lucena et al. J. Plant Nutr. Soil Sci. 2010, 173 (6), 900-906

HIGH MICRONUTRIENT CONCENTRATIONS

Our complexing agents allow for soluble micronutrient formulations with concentrations rivalling EDTA-chelated formulations. Lignosulfonates ensure that all the micronutrient content stays complexed even in challenging conditions. In the data below lignosulfonates deliver superior micronutrient solubility and complexed fraction compared to other organic complexing agents. 

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AA: aminoacid; GA: gluconate; H: humate: LS: lignosulfonate. % Soluble and % Complexed micronutrient analyzed according to EN 15962:2011
Source: Juan Jose Lucena, et al. J. Agric. Food Chem. 2007, 55 (14), 5746-5753

 

Enhanced micronutrient uptake

Marasperse® AG ensures proper foliar micronutrient levels all season long providing a stable, continuous release of complexed micronutrients into the leaf tissue, resulting in higher foliar levels and improved crop yield compared to EDTA. Its surface-active and hygroscopic properties allow it to capture moisture from the air and remain active on the leaf surface, ensuring efficient uptake without the risk of leaf scorch. 

 

 

Our products for micronutrient formulations

Frequently asked questions

  • What advantages does a lignin-based complexing agent offer over synthetic chelating agents such as EDTA?

    Borregaard's lignin-based complexing agent forms stable metal complexes across a wide pH range and can load higher concentrations of metal salts than other complexing agents. Compared with synthetic chelating agents such as EDTA, it provides a bio-based alternative for metal complexation, combining formulation performance with a favorable sustainability profile.

  • Does Borregaard offer ready-to-use complexed micronutrients or only the complexing agent?

    Both. In addition to the complexing agent for formulators, Borregaard offers a range of ready-to-use lignosulfonate-complexed micronutrients — including iron, copper, manganese, zinc and combinations — in powder, granular and liquid forms. These are approved as micronutrient fertilizers in most countries and Borregaard also has OMRI Listed products available for relevant markets.

  • What agronomic benefits do lignosulfonate-complexed micronutrients provide compared with non-complexed sources?

    Complexing micronutrients with lignosulfonates keeps them plant-available for longer and in a more stable form. Borregaard's complexed micronutrients are fully water-soluble and suitable for both foliar application and fertigation. They also supply organic carbon and soluble sulfur, supporting soil microbiology and healthy plant growth throughout the season. 

Find the right micronutrient solution 

 Our specialists can help you select the right lignin-based solution for your formulation requirements.