Soil organic carbon increases cereal yield stability regardless of tillage intensity

Le résumé fourni par la source

The temporal stability of yield, defined as the ratio between mean yield and standard deviation (SD) of yield across years, is a major agricultural goal under the current climate change scenario. Soil organic carbon (SOC) has a positive effect on crop yield, yet its role in buffering yield interannual variability—and whether tillage intensity modulates this effect—remains unclear. Using 54 tillage intensity comparisons (no-till vs. conventional till plots) from 26 medium‑ to long‑term field studies across 11 countries, covering four major cereal crops (C 3 : wheat and barley; C 4 : maize and sorghum), linear mixed‑effects models were applied to assess the relationship between SOC content, yield stability and its components (mean yield and SD yield), while controlling for climate, soil, and management covariates. The analysis quantified (i) SOC relationships with mean yield, SD yield and yield stability, and (ii) whether tillage intensity modifies these relationships. We found that SOC strongly increased yield stability (+18.9%) by increasing mean yield (+11.0%) and reducing SD yield (–15.3%). SOC was 6.1% higher in no-till compared with conventional till plots, but tillage intensity did not affect yield stability or its components. The interaction between SOC and tillage intensity was not significant when analyzing yield stability, indicating that SOC benefits on stability were similar across tillage intensities. Stability gains were most pronounced under low nitrogen inputs and water-limited conditions, highlighting SOC’s role as a resilience lever. Building SOC through sustainable practices such as no-till, cover cropping, residue retention, and diversified rotations offers a natural risk-reduction strategy, which is a fundamental target to reduce yield variability and insurance payments’ dependence under climate change.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.