Soil carbon sequestration – when aspirations and reality collide
Just a few weeks ago, we published a study stating that farm land soils, if managed properly, have the potential to sequester up to 7 billion tons of carbon dioxide; as much carbon as is emitted by the US transport sector.
These estimates, published in Scientific Reports, were based on recent global soil and land use maps, as a basis for scaling rational soil carbon sequestration rates at field-scale – tons of carbon sequestered per hectare per year – to the entire globe. Quite a simplification, of course, but good enough for showcasing the magnitude, and shedding light onto the considerably overlooked potential – in the soil!
However, to trap or “sequester”, carbon in the soil, the way we manage soils needs to change. Conventional agriculture is depleting soil health and fertility at an alarming rate, with either too little (sub-Saharan Africa) or overdosed (Europe, North America) inputs, excessive soil tillage and mono-cropping.
Two, rather well-known, improved management practices to halt such a trend are Conservation Agriculture (CA) and Integrated Soil Fertility Management (ISFM). CA combines practices that promote minimal soil disturbance, covering the soil through retention of plant residues, and crop diversification such as by planting two or more crops next to, or after, each other.
photo credit: Sterling College