Date

2017/02/07

Link

Link: GRDC Update paper

Organisations

Department of Primary industries and Regional Development

GRDC

Authors

Stephen Davies

Wayne Parker

Paul Blackwell

Bindi Isbister

Giacomo Betti

Chris Gazey

Craig Scanlan

Key messages

  • Subsoil compaction has increased in severity and depth in deeper sandplain soil resulting in substantial benefits from deeper ripping with average wheat yield increases of 35%.
  • Topsoil slotting behind deep ripping tines can encourage root penetration into the subsoil through providing nutrient and organic matter rich pathways and it is hoped this will improve the longevity of the benefits of deep ripping. Average wheat yield increase has been 53% with topsoil slotting.
  • Incorporating soil amendments and overcoming topsoil water repellence may require deeper soil mixing with ploughs or rotary spaders which modify the soil surface.
  • Overcoming multiple soil constraints can improve the longevity of benefits and overall returns on investment for up to 10 years at some sites.