Application of Iminodisuccinic Acid (IDS) in Soil Remediation, Nutrient Optimization, and Environmental Purification

Iminodisuccinic Acid (IDS), as a new-generation green polymer chelating agent, demonstrates outstanding chelation performance, excellent biodegradability, and strong environmental compatibility. Compared with traditional non-degradable chelating agents, it presents significant advantages and has become increasingly mature and widely applied in soil management and improvement.

Its molecular structure is rich in active functional groups such as carboxyl and amino groups, enabling it to address common agricultural challenges including soil degradation, nutrient imbalance, and pollutant accumulation through chelation, complexation, and ion exchange mechanisms.

Its primary application scenarios focus on three core directions: degraded soil remediation, soil nutrient optimization, and soil environmental purification. It is suitable for various soil types, leaves no residue throughout the application process, and does not disrupt soil microecology. This fully aligns with the requirements of modern green and sustainable agriculture. Relevant application results have been verified through multiple field trials and laboratory studies.

I. Degraded Soil Remediation: Improving Physicochemical Properties and Restoring Basic Soil Fertility

Long-term excessive fertilizer application, continuous cropping, and improper irrigation practices have led to increasing problems such as soil compaction, salinization, and acidification. These issues destroy soil structure, reduce fertility, and restrict healthy crop growth.

Iminodisuccinic Acid (IDS) functions as an environmentally friendly soil conditioning medium. Through both physical and chemical mechanisms, it restores degraded soils, gradually improving fundamental fertility and tillage performance without causing secondary pollution.

1. Saline-Alkali Soil Remediation

In saline-alkali soils, IDS effectively addresses salt accumulation through its chelation capability. Its active groups bind with excessive sodium and chloride ions, forming stable water-soluble complexes. These complexes can be leached into deeper soil layers with irrigation, reducing surface salt accumulation and lowering soil electrical conductivity.

This process alleviates salt stress on crop roots. Meanwhile, IDS promotes soil particle aggregation, forming stable soil aggregates that enhance aeration and water retention.

Studies show that under suitable conditions, continuous application for 2–3 growing cycles significantly reduces surface salinity and improves crop emergence and survival rates. Even in highly alkaline soils with pH values up to 10, it maintains over 85% chelation efficiency.

2. Compacted Soil Restoration

Soil compaction is often caused by the accumulation of insoluble precipitates formed by calcium and magnesium ions reacting with phosphate and carbonate.

IDS preferentially chelates calcium and magnesium ions, reducing precipitate formation and preventing further compaction at the source. It also breaks ineffective bonding between soil particles, optimizes pore structure, reduces bulk density, and improves soil workability.

Additionally, IDS promotes beneficial microbial activity, enhances organic matter decomposition, and strengthens soil water and nutrient retention capacity, creating a favorable environment for root development.

3. Acidified Soil Improvement

With its buffering capacity, IDS neutralizes acidic substances in soil and gradually adjusts soil pH toward neutral levels suitable for crop growth.

Its chelation function also immobilizes excessive aluminum and iron ions, reducing root toxicity and mitigating symptoms such as stunted growth and leaf chlorosis caused by soil acidification.

II. Soil Nutrient Optimization: Activating Nutrients and Improving Utilization Efficiency

Although soils contain abundant macronutrients (N, P, K) and micronutrients (Fe, Zn, Mn, Cu), many exist in fixed forms that are not directly available to crops. This leads to low fertilizer efficiency and nutrient waste.

With its strong chelation capability, Iminodisuccinic Acid (IDS) activates fixed nutrients, optimizes soil nutrient structure, and enhances nutrient availability without increasing fertilizer input. This supports the agricultural objective of reducing fertilizer usage while improving efficiency.

1. Micronutrient Activation

Iron, zinc, manganese, and copper are easily adsorbed by soil colloids or form insoluble precipitates. IDS forms stable, water-soluble chelates with these micronutrients.

These chelates migrate to the root zone and exhibit an “intelligent release” characteristic. When crop roots secrete organic acids, structural changes in the chelate trigger targeted micronutrient release for plant absorption, minimizing waste.

Practical results show that IDS can increase micronutrient utilization rates by 30–50%. It remains highly active in soils with pH values ranging from 4 to 9 and is particularly effective in alkaline and calcareous soils, alleviating iron chlorosis and zinc deficiency symptoms.

2. Macronutrient Synergistic Optimization

Nitrogen: IDS forms complexes with ammonium and nitrate nitrogen, reducing volatilization and leaching losses while extending nitrogen availability.

Phosphorus: It prevents calcium, aluminum, and iron ions from binding with phosphate, reducing phosphorus fixation and activating previously fixed phosphorus into plant-available forms.

Potassium: IDS promotes the decomposition of potassium-bearing minerals such as feldspar and mica, releasing available potassium while reducing adsorption fixation.

When used as a fertilizer synergist at a dosage of 0.3 wt%–5 wt%, IDS effectively activates fixed metal ions in soil without the need for additional micronutrient supplements. This meets crop nutrient requirements while reducing fertilizer production costs and maintaining soil ecological balance.

III. Soil Environmental Purification: Pollutant Degradation and Ecological Safety Protection

With increasing agricultural and industrial pollution, heavy metal contamination and chemical residues pose risks to soil ecosystems and food safety.

Thanks to its biodegradability and environmental compatibility, Iminodisuccinic Acid (IDS) plays an important role in soil purification by degrading pollutants and reducing environmental risks without causing secondary contamination.

1. Heavy Metal Remediation

As an environmentally friendly leaching agent, IDS chelates heavy metals such as lead (Pb), cadmium (Cd), mercury (Hg), and zinc (Zn), forming stable complexes that reduce metal bioavailability and plant uptake.

Under conditions of 10 mmol·L⁻¹ concentration and pH 5, after 240 minutes of leaching:

• Cadmium removal efficiency: 21.88%

• Lead removal efficiency: 17.47%

• Zinc removal efficiency: 9.21%

It effectively removes acid-soluble and reducible heavy metal fractions, significantly lowering environmental risks. Compared with traditional non-degradable agents, IDS is non-toxic, biodegradable, and does not damage soil structure.

2. Degradation of Chemical Residues

IDS enhances soil microbial activity, accelerating the degradation of pesticide and fertilizer residues.

Approximately 80% of IDS degrades within 7 days in natural soil environments, with biodegradation rates exceeding 70% within 28 days. Final decomposition products include water, carbon dioxide, and ammonia, leaving no harmful residues.

It is non-toxic and non-irritating, preserves soil microbial community structure, and improves soil self-purification capacity.

Conclusion

In summary, Iminodisuccinic Acid (IDS) combines strong chelation performance, excellent biodegradability, and environmental compatibility. Its mechanisms and practical validation support its application in:

• Degraded soil remediation

• Soil nutrient optimization

• Soil environmental purification

It improves soil compaction, salinization, and acidification; activates fixed nutrients; enhances fertilizer utilization; and safely mitigates heavy metal contamination.

Notably, its application does not require changes to existing agricultural practices. It is compatible with diverse soil types and cultivation systems, leaves no residue, and preserves soil microecology.

Its value is rooted in intrinsic physicochemical properties rather than promotional claims, offering a scientifically supported, environmentally sustainable solution for modern soil management and ecological protection.