Despite their previous use, around 30 million tonnes of carbon are still stored in organic soils. However, these soils are continually losing carbon – around 600,000 tonnes CO2-equivalent per annum in the case of those used for agriculture. Larger areas of agriculturally intensively used organic soils are found in flat, broad valley floors such as Switzerland’s Seeland region. Here, we quantified the carbon loss of a highly degraded, agriculturally managed former fen over a two-year period by means of micrometeorological methods. Further details can be found here:
ScienceDirect: Carbon budget response of an agriculturally used fen to different soil moisture conditions.
Since 2018, at a site in the St. Gallen Rhine Valley, we have been studying whether carbon loss in organic soils can be reduced – in spite of agricultural use – by ‘cover-sanding’ with mineral soil material. For this, CO2, methane and nitrous oxide greenhouse-gas exchange is being measured continuously over a period of several years. Using isotopes (14C), we can analyse the origin of the emitted CO2 and thus check whether the mineral cover protects the underlying peat from decomposition. Further details can be found here:
ScienceDirect: Soil carbon loss from drained agricultural peatland after coverage with mineral soil
The influence of mineral cover-sanding on the nitrogen cycle is being traced using isotopes (15N). Our measurements from both sites will be included in the Swiss Greenhouse Gas Inventory.