Publications

Our research group studies and quantifies the contribution of agriculture and land-use to greenhouse gas emissions in Switzerland, examines the effect of climate change, and explores options for adaptations in agricultural production. We use state-of-the-art micrometeorological and biogeochemical methods as well as mechanistic and statistical modeling.

Soils provide an important but fragile stock of carbon. My research explores the role of agricultural soils as sources and sinks for CO2 under different management and land-use techniques:

• System boundaries of sources and sinks. Carbon accumulation in an ecosystem at one site may occur at the expense of the stock at another site, for example by re-allocation of biomass. Scientifically sound budgeting requires consideration of the complete agricultural system.
• Mitigation options in organic soils. Organic soils form in intact mires and have a high carbon density; however, their carbon stocks destabilize after drainage. Agriculture and forestry on these soils release large amounts of CO2 and N2O over long periods of time. We study, in addition to re-wetting, options for the agricultural use of these soils that maintain the peat carbon stock.
• Mitigation via the use of biochar. Biochar is formed during pyrolysis and is relatively stable against microbial decomposition. It naturally occurs as charcoal in many soils and provides a long-lasting, stable carbon pool. Application of biochar may increase soil carbon stock, improve soil functionality, and reduce emissions of N2O.
• Carbon-nitrogen interactions. The excess of reactive nitrogen compounds released from agricultural activities has been long recognized as a threat, e.g. to many ecosystem services. Hence, increasing the soil’s carbon stock should not be at the expense of increasing nitrogen inputs. We study how soil carbon sequestration can be made more nitrogen-efficient.