Hemp Crop Soil Carbon Sequestration
topic
Hemp cultivation sequesters atmospheric carbon through above-ground biomass (10–15 tonnes dry matter/ha at 45% carbon content = 4.5–6.8 tonnes C/ha), root biomass (2–4 tonnes dry matter/ha), and root exudate-driven microbial biomass accumulation in soil. Soil organic carbon (SOC) increase under hemp rotation averages 0.3–1.2 tonnes C/ha/year (0-30 cm depth, measured by ISO 10694 Walkley-Black method) — 2–3× higher than wheat monoculture. Hemp's deep taproot system (1.5–2.5 m depth) improves soil structure, reducing bulk density by 5–15% and increasing water infiltration rate by 20–40% after 3-year rotation, mitigating erosion and improving drought resilience of subsequent crops. Mycorrhizal fungal colonisation of hemp roots (colonisation rate 40–65%) enhances phosphorus uptake and further increases soil carbon input through hyphal biomass. Carbon Farming Initiative (EU) and Voluntary Carbon Market protocols (Verra VCS, Gold Standard) are developing hemp-specific carbon credit methodologies with potential values of €15–50/tonne CO₂e sequestered, adding €200–600/ha additional revenue to hemp farmers beyond fibre sales.
Role
Hemp crop's dual role as fibre source and carbon sink positions it as a key regenerative agriculture tool for textile supply chain decarbonisation, with emerging carbon credit revenue streams improving farm economics and incentivising transition from conventional cotton cultivation.