Soil health alterations via compost additions to natural and remediated heavy metal-contaminated mineland soils

Author: mycolabadmin
6/3/2025
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Summary

Abandoned mining sites in Missouri left contaminated soils that couldn’t support plant growth. Researchers tested whether adding compost could restore these soils to health comparable to natural prairie. They found that applying 180 tons of compost per hectare successfully restored soil quality and plant growth while keeping heavy metal levels safe for livestock, making it an effective and affordable solution for healing mining-damaged lands.

Background

Historic mining operations in the Oronogo-Duenweg mining belt in southwest Missouri have caused heavy metal contamination (Pb, Cd, Zn) in soils. Remediation removed contaminated topsoil but exposed nutrient-deficient C horizons with elevated Cd and Zn concentrations that impede natural revegetation. This study evaluated compost application as a cost-effective remediation strategy for restoring soil health on contaminated mineland soils.

Objective

To evaluate the effectiveness of compost application at rates of 180 and 360 Mg ha⁻¹ in restoring soil health on remediated heavy metal-contaminated mineland soils using the Soil Management Assessment Framework (SMAF). The study compared compost-treated sites with naturally revegetated areas and native prairie benchmarks to assess reclamation success.

Results

Compost-treated soils exhibited overall soil health comparable to native prairie, both significantly greater than the natural revegetation site. The 180 Mg ha⁻¹ treatment provided optimal balance across indicators, with enhanced SOC, MBC, PMN, and nutrient availability. However, the 360 Mg ha⁻¹ rate resulted in excessive plant-available phosphorus. Plant heavy metal concentrations were below tolerable limits for livestock in all treatments.

Conclusion

Compost application at 180 Mg ha⁻¹ or lower is recommended for balancing phosphorus and metal concentrations while improving overall soil health to levels comparable with native prairie. The 0.01 M CaCl₂ extraction better predicted plant metal uptake than Mehlich-3, suggesting its use for metal bioavailability assessment in mine land reclamation. Lower application rates should be studied to extend compost utilization across larger contaminated areas.

Published in:Environmental Science and Pollution Research International,
Study Type:Field Study,
Source: 10.1007/s11356-025-36602-1, PMID: 40459821