Vetiver Grass and Atmospheric Carbon Storage and Sequestration
Vetiver produces a large quantity of biomass, both above ground and in its extensive root system. The amount varies considerably with location, soil, management, and climate. It’s important to distinguish two different claims here. Carbon storage refers to carbon held in that living biomass for as long as the plant or hedge persists; carbon sequestration refers to a smaller fraction of that carbon that becomes stabilized in soil organic matter over decades. There are published estimates that state the vetiver’s ‘sequestration‘ rate can run as high as 20-30 tons SOC/ha/year, but these figures typically measure biomass production or photosynthetic flux rather than stable, long-term soil carbon, and therefore should not be understood as sequestration rates. Drawing upon the work of Dr. Rattan Lal – the 2020 World Food Prize winner and head of the Rattan Lal Center for Carbon Management and Sequestration – on tropical grasses, a more defensible number is on the order of 1 ton of stable SOC/ha/year – meaning that over a decade a vetiver planting might potentially add as much as roughly 10 tons of stable SOC/ha. Separately, vetiver’s standing biomass represents a genuine and more readily defensible temporary carbon store, a category the EU’s carbon farming rules now recognize in its own right. TVNI is continuing to review the available research and will update this guidance as better long-term, vetiver-specific data become available.
Additional readings:
Soil carbon fractions under Vetiver grass in Australia and Ethiopia relative to other land uses.
Carbon Storage and Carbon Balance in Vetiver Grass Cultivation Areas in Northern Thailand