Deep-C storage: Biological, chemical and physical strategies to enhance carbon stocks in agricultural subsoils

Due to their substantial volume, subsoils contain more of the total soil carbon (C) pool than topsoils. Much of this C is thousands of years old, suggesting that subsoils offer considerable potential for long-term C sequestration. However, knowledge of subsoil C behaviour and manageability remains incomplete, and subsoil C storage potential has yet to be realised at a large scale, particularly in agricultural systems. A range of biological (e.g. deep-rooting), chemical (e.g. biochar burial) and physical (e.g. deep ploughing) C sequestration strategies have been proposed, but are yet to be assessed. In this review, we identify the main factors that regulate subsoil C cycling and critically evaluate the evidence…

• UD
  U.S. Department of Energy

  Awards: SCW1632, Contract DE-AC52-07NA27344, AC52-07NA27344
• LC
  Llywodraeth Cymru
• GR
  Grains Research and Development Corporation

  Award: DAW1801-001RTX
• LL
  Lawrence Livermore National Laboratory

  Awards: SCW1632, Contract DE-AC52-07NA27344, DE-AC52-07NA27344, AC52-07NA27344