Upland switchgrass enhances phytoremediation and promotes carbon sequestration in cadmium-contaminated soils

[Geoengineering News]

https://link.springer.com/article/10.1007/s11104-025-08071-5

Authors: Xintong Xu, Chao Xiao, Yadi Yu, Xiaokang Ni, Qingye Yu & Ling Zhang 

22 November 2025

Abstract

Aims

Soil cadmium (Cd) contamination and associated carbon loss are critical environmental issues. Switchgrass (Panicum virgatum L.) cultivation offers a solution by integrating phytoremediation with carbon sequestration.

Methods

We conducted a one-year pot experiment to evaluate two switchgrass ecotypes (upland and lowland) under nitrogen (N) regimes (0, 60 kg N ha−1) across five soil Cd concentrations (0, 1, 10, 20, and 30 mg kg−1). Biomass allocation, N uptake efficiency, Cd phytoextraction, greenhouse gas (GHG) emissions, and net ecosystem carbon balance (NECB) were systematically quantified.

Results

Under high Cd stress (30 mg kg−1), the upland ecotype showed stronger carbon sequestration stability with a more stable NECB by reducing 19% root/shoot ratio (RSR), whereas the lowland exhibited a significant decline, increasing its RSR by 26%. N application strongly promoted Cd phytoextraction, increasing it by 165% in the upland ecotype, though N2O emissions also rose by 22–57%. The upland also demonstrated superior carbon sequestration stability, with only a 6% increase in CO2 emissions under high Cd, versus 25% for the lowland.

Conclusions

Our findings underscore the superior capacity of the upland ecotype for simultaneous Cd phytoremediation and carbon stabilization, suggesting that ecotype-specific N management can optimize environmental outcomes.

Source: Springer Nature Link