A SoilsWest Seminar Series discussing the latest research and applications in the world of soil science with Prof. Davey L. Jones.

In this talk I will identify the main factors that regulate subsoil C cycling and evaluate the mechanistic basis of subsoil interventions designed to promote greater C storage. I will evaluate the barriers and opportunities for the implementation of strategies to enhance subsoil C sequestration and identify 5 key current gaps in scientific understanding.

Due to their greater depth, subsoils in agricultural systems often contain more carbon (C) than the topsoil. Subsoils are therefore increasingly being recognised as having characteristics that offer substantial potential for long-term C sequestration. Due to our incomplete knowledge of C behaviour in the subsoil, but especially of its manageability, this potential has yet to be realised. Although a range of physical (e.g. deep ploughing), chemical (e.g. iron amelioration, biochar) and biological (e.g. deep-rooting crops) management strategies have been proposed to enhance subsoil C storage, these approaches have not been critically evaluated or compared.