Global variation in soil carbon sequestration potential through improved cropland management

Area of Science:

• Agricultural Science
• Soil Science
• Environmental Science

Background:

• Improved cropland management is crucial for increasing soil organic carbon (SOC), enhancing soil fertility, and mitigating climate change.
• Limited spatially explicit data on management impacts hinders region-specific, climate-smart agricultural practices.
• Understanding SOC sequestration potential is vital for sustainable agriculture and climate action.

Purpose of the Study:

• To estimate the global SOC sequestration potential of improved cropland management practices.
• To identify regions with the highest potential for SOC sequestration.
• To provide insights for region-specific and climate-smart agricultural strategies.

Main Methods:

• Combined global meta-analytical results on SOC sequestration with spatially explicit data on current management.
• Assessed impacts of fertilization (organic vs. inorganic/none), tillage (no-till vs. intensive), and crop management (cover crops, residue incorporation).
• Analyzed regional differences based on yield gaps, initial SOC levels, and current practices.

Main Results:

• Estimated global C sequestration potential ranges from 0.44-0.68 Gt C yr-1 (maximum complementarity) and 0.28-0.43 Gt C yr-1 (realistic scenario).
• Lower realistic estimates are attributed to limited manure availability and adoption areas.
• Significant regional variations in sequestration potential were observed, linked to yield gaps, SOC levels, and recycling of residues.

Conclusions:

• Focusing on agricultural soils with large yield gaps and/or low SOC levels is most effective for boosting soil fertility and SOC sequestration.
• Targeted adoption of improved management practices, considering regional specificities, is key for maximizing SOC sequestration.
• The study provides a framework for optimizing land management for both agricultural productivity and climate change mitigation.