Synthesis on estimates of achievable soil carbon sequestration on agricultural land

Bodenprofil_Weizen. Photo: Gabriela Brändle, Agroscope, Switzerland

A new report has contributed to the Roadmap for EJP SOIL, by identifying the available knowledge of achievable carbon sequestration in mineral soils and mitigation of greenhouse gases (GHGs) in organic soils in agricultural land, including pasture and grassland.

The report is founded on an extensive gathering of information based on a questionnaire, where all 25 participating countries have contributed with data, reports, scientific papers, including commercial and grey literature.

The stocktake shows that there has been a clear increase in interest for topics covering soil carbon sequestration for climate change mitigation in the last two decades. Increasing studies and a total of 114 ongoing projects have been reported dealing with soil carbon sequestration (SCS) and GHG mitigation measures.

Country-based knowledge still poor

However, the stocktake also shows that availability of datasets concerning SCS is variable among Europe. While Northern Europe and Central Europe is relatively well studied, there is a lack of studies comprising parts of Southern, Southeastern and Western Europe.

At present, country-based knowledge and engagement is still poor, and only half of the countries can provide information on achievable carbon sequestration at national and regional scales. This information is mostly based on rough estimates without consideration of technical and socio-economic feasibilities, such as the availability and suitability of land, the costs or profits for farmers and the willingness of implementation by farmers, which are key for sustainable implementation. However realistically estimate carbon sequestration is a challenging task involving transdisciplinary knowledge and the support of a variety of stakeholders.

Climate change usually not included

Furthermore, climate change is usually not included in the provided information, although it is known that it could have important impacts on carbon stocks.

The presented national SCS potentials do however point towards potentially important contributions to mitigate climate change by covering considerable shares of national greenhouse gas emissions from the agricultural sector in the range of 0.1-27 %, underpinning the importance of further investigations.

In contrast to mineral soils, effective mitigation measures for organic soils while maintaining industrial agricultural production are still in its infancy. Very few mitigation options exist to mitigate GHG emissions without compromising agricultural production.

Most GHG mitigation practices reported by the countries involve the restoration of organic soils, which means a complete abandonment of land from any agricultural use. Only one contribution reports possible mitigation potentials, which are based on specific water management measures (water level fixation). Nevertheless, there is an increasing awareness of the need of mitigation measures reflected by the several ongoing research projects on peatland management.