A new study found the base rate of organic carbon decomposition in soil across the US can vary by as much as tenfold.
Soil carbon decomposes at wildly different rates—up to tenfold—even under identical conditions, driven by soil minerals and microbes often ignored in climate models.
By incubating soils from across the U.S. and using machine learning, researchers identified key controls like fungi and iron/aluminum minerals.
They created high-resolution maps showing strong regional differences in soil carbon decay and retention. Including these variations in Earth system models could sharpen climate projections and guide smarter soil carbon conservation policies.
Biochar-Based Fertilizers Increase Soil Organic Carbon Stability and Fungal Residual Carbon by Over Twenty Percent
The study shows that long-term, low-dose biochar and biochar-based fertilizers can significantly improve soil organic carbon quality and stability.
These treatments increase resistant aromatic carbon forms, strengthening soil structure and creating a more durable carbon reservoir.
Biochar-based fertilizers enhance the microbial carbon pump, especially boosting fungal-derived carbon that forms stable soil organic matter.
Overall, this approach offers a practical, low-cost strategy for improving soil fertility while supporting long-term carbon sequestration.
Cultivation Management Reshapes Soil Profile Configuration and Organic Carbon Sequestration: Evidence from a 45-Year Field Study
Long-term cultivation reshaped SOC distribution across 0–200 cm, with SOC decreasing exponentially with depth and remaining consistently lower than in adjacent forest soils.
Surface soils (0–78 cm) accumulated carbon under tillage, but at only half the rate of forest, while subsoil and deeper layers experienced significant SOC depletion.
SOC controls differed by land use: forest SOC was linked to clay content, whereas cropland SOC was driven by nitrogen, texture, bulk density, and pH.
Overall, cultivation thickened the plough layer and promoted surface carbon enrichment at the cost of accelerated deep-soil carbon loss.