Sulfur Fertilizer Redox Potential Modulation in Plant Tissue

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Solution Overview

Problem

Agricultural practices lack effective strategies for managing and modulating soil and plant redox potential (Eh), which affects nutrient availability, plant stress tolerance, and overall plant performance, despite the importance of oxidation-reduction reactions in plant and soil systems.

Innovation Solution

The use of sulfur fertilizers such as thiosulfates, polysulfides, sulfides, sulfites, metabisulfites, dithionites, and elemental sulfur to decrease the redox potential of plant tissue, applied either to soil or foliage, achieving significant reductions in redox potential while maintaining soil pH.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional sulfur fertilizers (sulfate) are applied to soil, then sulfur nutrition is provided to plants, but redox potential of soil and plant tissue remains unchanged

Engineering Contradiction:
Improvesulfur nutritionVSAvoidredox potential control
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies sulfur fertilizers in different chemical forms (thiosulfate, polysulfide, sulfide, sulfite, metabisulfite, dithionite, elemental sulfur) that have different oxidation states and reducing capacities. By selecting specific sulfur compounds with appropriate reducing power, the patent successfully modifies soil and plant redox potential while providing sulfur nutrition, resolving the contradiction between sulfur supplementation and redox control.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If sulfur fertilizers are applied to reduce redox potential, then plant stress resistance and antioxidant content increase, but soil pH may be reduced

Engineering Contradiction:
Improvestress resistanceVSAvoidpH reduction
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies sulfur fertilizers at controlled rates and frequencies to achieve partial reduction of redox potential without excessive acidification. By using multiple application events at moderate doses rather than single high-dose applications, the patent maintains stress resistance benefits while limiting pH reduction to acceptable levels.

Inventive Principle:
Principle #16Partial or excessive action

3Quantity of substance

If thiosulfate is converted to sulfate by rhizosphere microbiome before root uptake, then sulfur is made available to plants, but redox potential modulating effect is lost

Engineering Contradiction:
Improvesulfur availabilityVSAvoidredox potential effect
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies sulfur fertilizers directly to foliage (foliar application) or uses formulations that protect against rapid microbial conversion, ensuring the redox-active form reaches the plant before complete conversion to sulfate. This preliminary action preserves the reducing capacity needed for redox modulation while still providing sulfur nutrition.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses foliar application as an intermediary pathway that bypasses the rhizosphere microbiome conversion process. By applying sulfur compounds directly to leaves, the patent eliminates the microbial conversion step that would otherwise destroy the redox-modulating effect, while still achieving sulfur uptake by the plant.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The methods and uses provide improved control over soil and plant redox potential, enhancing plant health, stress resistance, reducing oxidative stress, and increasing antioxidant content, while avoiding pH reduction, with effects lasting up to several weeks.

Implementation Method 1

the present inventors have surprisingly found that these compounds, which contain a so-called 'reducing sulfur' are capable of significantly influencing the soil redox potential (Eh) when applied at regular agronomical rates

Methodology Applied
Scientific EffectRedox reactions: Redox Reactions

Data Source

PatentEP4426794B1Agricultural use for the reduction of redox potential in plant tissue
Publication Date: 2025.12.31 TESSENDERLO GROUP NV

AI summary

The present invention relates to methods and uses for the modulation of the redox potential of soil and/or plant tissue comprising the application of sulfur fertilizers selected from the group consisting of thiosulfates, polysulfides, (bi)sulfides, (bi)sulfites, metabisulfites, dithionites, elemental sulfur and combinations thereof.