Research & Monitoring / Carbon Pathway Draft Hub / TT-OS Methodology

Carbon Sequestration Metrics in Cacao Agroforestry

Regenerative cacao agroforestry can contribute to climate mitigation by storing carbon in trees, roots, soil and organic matter. At the Elegguá Project, carbon monitoring is not treated as a marketing claim. It is treated as evidence: measured, time-stamped, confidence-scored and linked to TT-OS verification methods.

Cacao Elegguá Farm is a 136.4-acre agroforestry site in Kenema, Sierra Leone. Its cacao systems, companion crops, shade trees, soil regeneration practices and biodiversity monitoring provide a practical field base for developing carbon sequestration metrics under TT-OS.

Why Carbon Sequestration Matters at Elegguá

• Climate mitigation: multi-layer agroforestry systems can store carbon across biomass, roots, litter and soil.
• Soil regeneration: carbon-rich soils improve water retention, nutrient cycling and ecological resilience.
• Economic potential: high-integrity monitoring may support future premium markets, research partnerships or carbon pathway feasibility.
• TT-OS integration: carbon metrics feed directly into Plant Intelligence Passports, especially the Ecological Performance factor.
• Evidence discipline: TT-OS separates observed evidence, estimated values, regional comparison figures and unverified claims.

Carbon Pools We Monitor

Typical Sequestration Rates in West African Cacao Agroforestry

Regional studies suggest that mature shaded cacao agroforestry systems can hold substantially more carbon than simplified full-sun systems. These values are useful for planning, but they are not treated as Elegguá site results until field measurements confirm them.

• Total carbon stocks: mature shaded systems are often discussed around 100–150+ Mg C/ha, depending on age, density, species mix and methodology.
• Annual sequestration: biomass-focused estimates may vary widely, sometimes around 1.3–6+ Mg C/ha/year depending on system design and maturity.
• Soil carbon: shaded, organic-matter-rich systems may store more SOC than simplified monocultures, but reliable comparison requires sampling depth, SOC concentration and bulk density.
• Scaling potential: shade-tree adoption across cacao landscapes could have climate relevance, but livelihood security, biodiversity, tenure and verification integrity must remain central.

Our Measurement and Monitoring Methods

1. Biomass Carbon Estimation

• Measure tree diameter at breast height where appropriate.
• Measure or estimate tree height in sample plots.
• Record species identity, plot ID, block ID, canopy layer and management context.
• Apply allometric equations, using species-specific or regionally appropriate equations where justified.
• Convert biomass to carbon using a documented dry-biomass carbon fraction.
• Convert carbon to carbon dioxide equivalent where required using the molecular weight ratio: CO2e = C × 3.67.

2. Soil Carbon Monitoring

• Composite soil sampling from multiple sub-samples per plot.
• Soil pit or profile photography where practical.
• Laboratory testing for soil organic carbon concentration where available.
• Bulk density and sampling depth recording for stock calculation.
• Supporting soil indicators including pH, texture, organic matter, moisture context and root density.
• Integration with TT-OS soil intelligence, Plant Passports and ecological confidence scoring.

3. Additional Metrics

• Canopy cover and tree density.
• Litter layer depth and quality.
• Mulch, compost, biochar and organic residue records.
• Species diversity and companion planting structure.
• Time decay applied to older observations.
• Multi-observer checks, GPS context and photo documentation.

Sample Metrics from Our Site

Elegguá site metrics are treated as emerging data. Public reporting must distinguish between direct measurements, estimates, regional comparison values and future projections.

Integration with TT-OS

• Plant Intelligence Passports: record species identity, ecological role, shade function and biomass relevance.
• Soil Intelligence: records SOC, organic matter, bulk density, pH, texture and profile evidence.
• Confidence Scoring: weights ecological performance and applies time decay to older data.
• Bayesian modelling: can represent plot-level uncertainty, block differences and confidence intervals.
• Cash-flow and risk modelling: can test future carbon scenarios without treating them as guaranteed income.
• Impact Reports: can publish annual monitoring summaries with clear evidence boundaries.

Future Directions

• Expand soil probes and microclimate monitoring.
• Create carbon pool charts and sequestration-over-time visualisations.
• Develop a simple educational carbon calculator teaser.
• Train community monitors in carbon-smart agroforestry practices.
• Explore carbon credit certification pathways only after evidence, land, cost, governance and third-party validation readiness are clearer.
• Research optimal companion species for carbon, soil, shade, biodiversity and livelihoods without assuming yield trade-offs away.

Suggested Links and Calls to Action

• TT-OS Methodology
• Soil Health Verification
• Research & Monitoring
• Carbon Pathway Draft Hub
• Bayesian Hierarchical Modelling
• Cash Flow & Risk Modelling

Carbon sequestration is one co-benefit of regenerative agroforestry alongside biodiversity, soil health, food resilience, field education and sustainable livelihoods. TT-OS keeps those benefits visible, measured and updateable.