A field study: Vermicompost mitigates Cd migration in soil-celery system

Cadmium (Cd) contamination of agricultural lands jeopardizes soil quality and food safety. The field study evaluated the effect of pure vermicompost (VK), vermicompost amended with struvite (VS) and vermicompost amended with biochar (VB) applied to cadmium contaminated soil on celery (Apium graveolens L.) growth, soil to plant Cd migration, and soil properties. The results indicated that, compared to no amendment (CK) and VK, VS and VB enhanced celery growth and reduced Cd soil-to-plant migration by lowering Cd bioavailability and transport coefficients. Both VS and VB significantly increased soil properties including pH and organic matter (OM) that played a vital role in immobilizing Cd and preventing its transfer from soil to celery. Besides, amended vermicomposts increased soil bacterial diversity and enriched metal-resistant taxa (e.g., Firmicutes, Proteobacteria, Myxococcota, etc). Thus, VS and VB have strong potential for remediating Cd-contaminated soils. • Vermicomposts from cow dung amended with struvite or biochar were applied in Cd-contaminated soil. • Amended vermicomposts increased celery growth and inhibited its Cd uptake. • Amended vermicompost enhanced both soil pH and OM. • Amended vermicomposts increased the abundances of metal-resistant bacteria. • Amended vermicomposts have potential as effective remediation materials for Cd-contaminated soils.