Agricultural soils in climate change mitigation: comparing action-based and results-based programmes for carbon sequestration

Removing greenhouse gases from the atmosphere is a major challenge for today’s society. A great source of potential for greenhouse gas sequestration is beneath our feet: agricultural soil. By accumulating soil organic carbon in soil, farmers can sequester carbon dioxide and simultaneously reach soils more resilient to extreme weather events. To encourage farmers to build up humus and thus sequester carbon, some humus programmes have been developed by non-governmental organisations. In this regard, action-based reward systems are on their way to challenging the established results-based approaches. Against this background, we analyse how action-based and results-based approaches, as well as other crucial features of humus programmes, affect farmers’ willingness to participate in a humus programme. We conducted a Discrete-Choice-Experiment and analysed it using a mixed logit model. The results show that farmers have a statistically significant preference for action-based humus programmes, shorter programme durations, higher incentives, and an annual and government-funded payment. More specifically, farmer participation is twice as likely if humus formation is rewarded for action rather than results. The willingness-to-accept calculation indicates that a results-based humus programme would cost the funding agency about €20 more per ton of carbon dioxide sequestered in the soil. Above all, humus programmes with an action-based approach and annual payments would increase farmers’ willingness to participate. Our results contribute to the development of targeted humus programmes and policies to increase carbon sequestration in agricultural soils.