Limited potential of no-till agriculture for climate change mitigation

• Published in: Nature climate change Vol. 4; no. 8; pp. 678 - 683
• Main Authors: Powlson, David S., Stirling, Clare M., Jat, M. L., Gerard, Bruno G., Palm, Cheryl A., Sanchez, Pedro A., Cassman, Kenneth G.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2014; Nature Publishing Group
• Subjects: 704/106/694/682; Agricultural practices; Agriculture; Agronomy. Soil science and plant productions; Biological and medical sciences; Carbon sequestration; Climate Change; Climate change mitigation; Climate Change/Climate Change Impacts; Climatology. Bioclimatology. Climate change; Earth, ocean, space; Environment; Environmental Law/Policy/Ecojustice; Exact sciences and technology; External geophysics; Fundamental and applied biological sciences. Psychology; Meteorology; Organic carbon; perspective; Soil properties; Soil quality; Soil science; agriculture; sustainable development; Mitigation; Carbon stock; global change; climate warming; Zero tillage; Climate policy; Carbon sequestration; climate change
• ISSN: 1758-678X; 1758-6798
• DOI: 10.1038/nclimate2292

No-till agriculture is generally considered good for soils, and probably also beneficial in relation to climate change adaptation. However, this Perspective argues that the potential for climate change mitigation through soil carbon sequestration that is possible from a change to no-till agriculture has been widely overstated. The Emissions Gap Report 2013 from the United Nations Environment Programme restates the claim that changing to no-till practices in agriculture, as an alternative to conventional tillage, causes an accumulation of organic carbon in soil, thus mitigating climate change through carbon sequestration. But these claims ignore a large body of experimental evidence showing that the quantity of additional organic carbon in soil under no-till is relatively small: in large part apparent increases result from an altered depth distribution. The larger concentration near the surface in no-till is generally beneficial for soil properties that often, though not always, translate into improved crop growth. In many regions where no-till is practised it is common for soil to be cultivated conventionally every few years for a range of agronomic reasons, so any soil carbon benefit is then lost. We argue that no-till is beneficial for soil quality and adaptation of agriculture to climate change, but its role in mitigation is widely overstated.