Indicators for successful carbon sequestration and greenhouse gas mitigation by rewetting cultivated peat soils
Indicators for successful carbon sequestration and greenhouse gas mitigation by rewetting cultivated peat soils (INSURE)
Drainage and agricultural use of peatland soils turn greenhouse gas sinks into greenhouse gas sources. INSURE is investigating whether this situation can be reversed through rewetting.
State-of-the-art techniques are used to measure the greenhouse gas balances of drained and adjacent rewetted peatland sites in the five participating countries. The gases to be measured are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). It is expected that CO2 emissions in particular will be greatly reduced when the peat is re-saturated with water, while methane emissions will increase. The balance of these two gases determines the extent to which rewetting improves the overall situation.
In addition to the major role played by the water table, the chemical and molecular composition and stability of peat play a potentially important role in CO2 and methane emissions from organic soils of former peatlands. High levels of easily degradable material potentially increase methane emissions. Using cutting-edge analytical methods, Agroscope investigates peat composition and compares it with greenhouse gas fluxes in the field.
Gas measurements are taking place at several locations. However, since we would like to be able to make generally valid statements about the effectiveness of rewetting for the greenhouse gas balance of peat soils, we are investigating whether the measured data can be correctly reproduced by means of two complex mathematical models simulating plant growth and soil properties in high resolution. A successful simulation would allow such models to be used for estimation at higher spatial scales.