Soil contains a huge amount of carbon, twice as much as in the atmosphere in the 0-30 cm layer alone. However, continuous cultivation over a long period has reduced stocks of soil organic carbon (SOC, which I will abbreviate here to soil carbon), often to dangerously low levels. The EU’s Joint Research Centre estimates that some 45% of the soils of Europe have a low or very low organic matter content (0-2% organic carbon). The main mechanism for soil carbon loss is associated with ploughing, due to increased decomposition of SOC due to soil aeration and soil aggregate destruction, increased aggregate turnover and a reduction in aggregate formation.
Reversing this process to build up soil carbon stocks has thus the technical potential to sequester a lot of carbon. The practices to do this are now well known: they include the use of winter cover and catch crops; crop rotation; adding legumes or N-fixing crops; reduced or zero tillage; and incorporating crop residues and other organic matter.… Read the rest
Incentivising soil carbon sequestration
