Soil organic matter storage in temperate lowland arable, grassland and woodland topsoil and subsoil

Soils are the largest terrestrial pool of organic carbon, with up to 50% soil carbon (SOC) stored below 30 cm. Knowledge impact land use on mechanisms by which SOC is in subsoils critical developing and delivering strategies mitigate climate change. We characterized under arable, grassland, deciduous woodland uses lowland England determine how affects topsoil subsoil protected. Soil matter (SOM) physical fractionation ammonium oxalate extractable Al, Fe Mn were analysed elucidate protection mechanisms. Results revealed that mineral-free particulate (fPOM) fraction was significantly greater both than grassland or arable. The mineral-associated (MinOC) proportionally compared all uses, arable >grassland > woodland. These findings indicate extent protected, woodlands containing a higher proportion has less from decomposition. Subsoil protected decomposition organo-mineral interactions amorphous Mn, may be susceptible future pH shifts as result This study highlights need consider change SOC, given policy public interest planting for mitigation.