European study shows positive effect of reduced tillage on carbon storage in organic farming systems.
The value of long-term studies can be found when you’re ready to dig deep. WUR scientists and European partners asked: what happens when organic farmers stop ploughing? In a joint effort, we sampled nine field trials across Europe and assessed the impact of reduced tillage versus ploughing on soil carbon storage: Humus was always enriched in the soil surface layer in reduced tillage systems, which is essential to protect soils from erosion and helps rain to infiltrate faster.
However, in the old plough layer and below (ca. 15-50 cm), humus stocks decreased at most sites. Summing up, some sites showed an overall gain in humus, some not. On average, the relative C storage increase was 90 kg per ha and year in the depth of 0 to 50 centimetres.
Combining reduced tillage with organic farming practices is thus a tool to care for our soils with a small potential to mitigate but a great opportunity to adapt to climate change.