Know more

One of the aims of CIRCASA project is to create a Scientific Research Agenda (SRA) for 2020-2025 and to do so, experts of the project have identified the scientific challenges around soil carbon sequestration in agriculture.  In this particular report, authors gathered 14 science-based challenges identified from literature and evaluated through a questionnaire addressed to the scientific community. This work looks forward to achieving consensus on future research priorities and activities at European and International levels by creating an International Research Consortium.

Soil organic carbon in agriculture

Soils are the biggest reservoir of carbon containing nearly twice as much carbon as the atmosphere, however, this precious carbon pool has lost 116 Gig atones of carbon since the advent of agriculture. Due to inappropriate land management, world’s soils are getting poorer, losing their capacity to store organic carbon and releasing more and more carbon to the atmosphere: a real issue to actual climate change crisis.

However, agricultural soil’s potential to store soil organic carbon (SOC) through judicious agricultural managements is possible and has multiple co-benefits for the ecosystem services, food security, soil stability and healthy among others. Nevertheless, a political and scientific frame is necessary to implement good practices allowing SOC storage, a nature-based solution for climate change mitigation.

14 Challenges to soil carbon sequestration research

Fourteen challenges were identified within three main themes at different physical scales (from molecular to regional and global scale). Those challenges limit the ability to predict soil carbon changes as well as prescribe and adopt the best land management practices. 

In order to prioritize challenges for future research depending on the knowledge gaps and importance given to different challenges, researchers were asked to respond to a questionnaire.

Unfortunately, even if this work provides valuable information about soil researcher’s perception of the level of knowledge in the field of SOC sequestration, it is difficult to understand the relationships between the questionnaire responses and the respondent profiles. Data results from this work do not allow us to justify prioritization of challenges for future research.

“All challenges seem legitimate and useful directions for future research into agricultural soil carbon sequestration.”

Testable Hypothesis to address challenges

Thus, to address the different intellectual, logistical, and technical challenges to implement the best land management practices for soil carbon sequestration, CIRCASA project proposes twelve testable hypotheses:

1. Organic carbon preservation is the result of the interplay between mineralogical and microbiological processes.
2. For a given soil type, there exists a finite amount of carbon that can be stabilised through organo-mineral interactions.
3. Living soils have a net positive impact on soil organic carbon persistence.
4. Calculating the ratio of soil carbon sequestration to nitrogen release will enable the realisation of agricultural greenhouse gas budgets.
5. The persistence of deep soil organic carbon is governed by soil microbial activity.
6. Changes in soil organic carbon stocks can be measured accurately with design-based sampling and a standardised methodology.
7. Combining crop, livestock, and tree production in mixed agroforestry systems stabilises more soil organic carbon than when separate in production.
8. Sustainable intensification using agroecological approaches can reduce soil organic carbon (SOC) loss and restore SOC in depleted soils.
9. Agricultural soil carbon erosion can be minimised while maintaining connected environments.
10. Soil organic carbon has inherent value through regulation of ecosystems services.
11. The lack of soil governance will limit agricultural soil carbon sequestration.
12. Stakeholder engagement, knowledge exchange and learning can help to overcome socio-cultural barriers to increase soil organic carbon

If the challenges in question are addressed, this could contribute to climate mitigation besides to provide multiple co-benefits. Furthermore, this will build resilience of agricultural production. By optimizing the best agricultural practices recommendations, farmers and land managers will be benefited. Last but not least, soil carbon sequestration will help to take steps towards at least 5 of the 15 UN Sustainable Development Goals such as goal 2 (Zero hunger), goal 3 (Ensuring healthy lives and promoting the well-being at all ages), goal 6 (Ensure clean water and sanitation), goal 13 (Climate action), and goal 15 (protecting and preserving life on land).

Know more about how soil carbon sequestration responds to the UN SDG’s and SOC sequestration co-benefits on the Koronivia Joint Work on Agriculture (KJWA) submission:

KJWA submission provides scientific guidance to increase Soil Organic Carbon stocks

Download the full report https://www.circasa-project.eu/content/download/3914/38020/version/1/file/D1.3%20The%20science%20base%20of%20a%20strategic%20research%20agenda.pdf