Farming systems that do not till the soil, otherwise known as “no-till,” have been actively promoted by international research and development organizations to conserve soils and by this, ensure food security, biodiversity and water conservation. The FiBL study scientifically examines no-till, as it is currently practiced and specifically analyses no-till’s contribution to climate protection and whether its practice effectively sequesters carbon and mitigates climate change.
While the scientific literature shows that no-till positively contributes to soil protection and stable yields in many parts of the world, research on the climate benefits of no-till remains inconclusive. Soil carbon sequestered in the accumulated organic matter in the topsoil is restricted to the upper 10 cm of the soil. At soil depths below 20 cm no-till systems show no difference or even sometimes a deficit when compared with tillage systems.
There is no evidence that empirically shows that no-till reduces greenhouse gas emissions in croplands.
Furthermore no-till farming systems often rely on heavy agrochemical use and often use genetically modified organisms. Herbicides are used to control weeds that would otherwise be controlled by tillage or diversified crop rotations. Investments in expensive equipment and the skill for correct agrochemical handling make no-till often unsuitable for small-holders in southern countries.
Given the uncertainties and mixed results of no-till’s climate impacts and the negative impacts of herbicides and genetic engineering, the authors of the study recommend that no-till and reduced tillage should be excluded from the carbon market unless reliable carbon offset quantification and monitoring can be introduced and assure important sustainability criteria, such as food security, rural livelihood provision, biodiversity, and environmental protection.
The authors see a great potential to focus research and policy on reduced tillage compatible with sustainable and organic agriculture systems.
The study was commissioned by Misereor and is available at Andreas Gattinger, FiBL Switzerland
The study
Andreas Gattinger, Julia Jawtusch, Adrian Müller, Paul Mäder: No-till agriculture –a climate smart solution? Climate Change and Agriculture Report No. 2. Misereor, Aachen. Compiled by the Research Institute of Organic Agriculture (FiBL), Frick. Available at http://m.misereor.de/fileadmin/redaktion/MISEREOR_no%20till.pdf