Beyond the crop: the role of medicinal and aromatic plants in soil carbon sequestration and nitrogen cycling

Medicinal and aromatic plants (MAPs) play a critical yet underexplored role in enhancing soil functionality through their unique phytochemical interactions and ecological adaptability. This review synthesizes current research on how MAPs influence soil carbon sequestration and nitrogen cycling, positioning them as multifunctional agents in sustainable agroecosystems. Unlike conventional crops, MAPs release complex secondary metabolites, such as flavonoids, alkaloids, terpenoids, and phenolics, which modulate microbial diversity, enzymatic activity, and nutrient transformation. These compounds shape the rhizosphere microbial communities, facilitate nitrogen fixation and mineralization, and contribute to soil organic matter (SOM) stabilization through rhizosphere priming and humus formation. Integrated approaches, such as intercropping, agroforestry, and organic amendments, enhance these benefits, while mitigating allelopathic effects and improving carbon and nitrogen fluxes. This review further explores technological innovations including remote sensing (RS), biochar applications, and nanotechnology, which support MAP-based climate-resilient agriculture. Case studies across diverse geographies demonstrate MAPs' potential to restore degraded soils, reduce greenhouse gas emissions, and improve phytochemical yields. Overall, MAPs offer a promising model for regenerative, low-input farming systems that align ecological integrity with economic viability. By actively engineering the soil environment, MAPs emerge not only as botanical resources but also as ecological catalysts in the transition to sustainable agriculture.