Practice Abstract - Research and innovation

Soil carbon stewardship and Nature-based solutions: Managing Soil organic carbon

Soil organic matter (SOM) is ~50% carbon; the rest includes nutrients like N, P, S, O, and H that support microbial life. Microbial activity enhances soil structure, water retention, aeration, and root growth, making SOM a vital nutrient reservoir. Most carbon is stored in soils, so soil organic carbon (SOC) plays a key role in climate regulation. Yet, SOC is easily lost through conventional farming, which disrupts soil structure and hinders carbon replacement. Effective land management is essential to make soils reliable carbon sinks. However, knowledge gaps remain about which practices, or combinations, best enhance SOC. Promising options include reduced tillage, perennial crops, cover cropping, managed grazing, manure or compost application, and residue retention. The impact of any NBS depends on how it's combined with others. Rothamsted's LSRE tests systems integrating compost, cover crops, reduced tillage, and perennials. 

Even small increases in SOM and SOC benefit soil health, boosting water and nutrient use efficiency, soil structure, and biodiversity (e.g. earthworms). In the global north, carbon-rich soils must be responsibly managed. Globally, soils (mainly agricultural) could sequester over a billion additional tons of carbon per year. Nature-Based Solutions (NBS), like those tested in Rothamsted's LSRE, support SOC and SOM through practices such as reduced tillage, residue retention, compost and manure application, and leys in crop rotations. These practices enhance microbial activity and nutrient cycling, contributing to long-term soil and planetary health. NBS create favorable conditions for sustaining soil function and resilience. SOM is typically measured via Loss on Ignition (burning off organic matter), while SOC is more precisely assessed using the Dumas method (dry combustion), which quantifies CO₂ released by heating soil in oxygen-rich air.

 

Additional information

The Rothamsted Research Large-Scale Rotation Experiment (LSRE) tests multiple Nature-Based Solutions (NBS), such as crop rotations, diversified cropping, minimal/zero tillage, and organic amendments, applied in combinations to assess their effects on soil properties, especially SOC and SOM. LSRE monitors synergies, trade-offs, crop yields, and fertilizer use efficiency. SOC must be measured over time, as weather causes seasonal fluctuations. While all treatments showed short-term SOC decreases, long-term results highlight the consistent benefits of NBS, confirming the value of long-term trials. SOC often rises in rotation phases with NBS input (e.g. compost) and falls in others; thus, benefits are assessed at the full-system level. After six years, the top five systems for SOC all combined compost with reduced tillage, even on sandy soils with limited storage capacity. Larger impacts are expected at the clay soil LSRE site. Managing SOC requires strategies like reduced tillage, cover crops, livestock integration, compost, and residue retention—all of which enhance SOM, soil structure, and ecosystem services like water retention and reduced input loss.

Challenges

  • LSRE does not include livestock integration, so not representative of a mixed system.
  • Challenges in removing cover crops and perennial lays without tillage.
  • Over-reliance onglysophate.
  • Extreme weather and establishing cover crops in time for growing season.

Resources 

  • Direct drilling machinery appropriate to soil type.
  • Access to livestock manure and/or livestock plus livestock infrastructure.
  • Access to green compost.
  • Appropriate varieties for diversified cropping rotations.
Source Project
Transformation for sustainable nutrient supply and management
Ongoing | 2022-2026
Main funding source
Horizon Europe (EU Research and Innovation Programme)
Geographical location
Denmark, Germany, Hungary, Netherlands, Romania, Switzerland, The United Kingdom, China
Project details

Project Keywords

Links