Declines in soil carbon storage under no tillage can be alleviated in the long run

Improved management of agricultural soils plays a critical role in mitigating climate change. We studied the temporal effects of the adoption of no-tillage (NT) management, often touted as an important carbon sequestration strategy, on soil organic carbon (SOC) storage in surface and subsurface soil layers by performing a meta-analysis of 1061 pairs of published experimental data comparing NT and conventional tillage (CT). In the early years of adoption, NT increased surface (0-10 cm) SOC storage compared to CT but reduced it in deeper layers leading to a decrease of SOC in the entire soil profile. These NT-driven SOC losses diminished over time and the net change was approaching zero at 14 years. Our findings demonstrate that NT is not a simple guaranteed solution for drawing down atmospheric CO2 and regenerating the lost SOC in cropping soils globally and highlight the importance of long-term NT for the recovery of initial SOC losses.

Automated summary

Improved management of agricultural soils is crucial in mitigating climate change. A meta-analysis of 1061 pairs of published experimental data comparing no-tillage (NT) and conventional tillage (CT) showed that in the early years, NT increased soil organic carbon (SOC) storage in the surface layer but decreased it in deeper layers, resulting in an overall decrease in SOC in the entire soil profile. However, these NT-driven SOC losses diminished over time and the net change approached zero after 14 years. This study highlights the importance of long-term NT for the recovery of initial SOC losses and suggests that NT is not a simple solution for carbon sequestration.