Quantifying and alleviating subsoil compaction in arable soils

Quantifying and alleviating subsoil compaction in arable soils

By Cranfield University

Intensive agriculture has increased the risk of subsoil compaction. Estimates predict that over a third of EU farmed subsoils may already be detrimentally affected by subsoil compaction. The impact of this is seen when it negatively affects soil functions such as drainage because it limits percolation, production through reduced crop vigour caused by restricted root growth, and affects the wider environment through increased flooding and runoff. Subsoil compaction remains difficult to quantify at field-scale and mechanical alleviation, although effective, weakens soil structure and increases the risk of recompaction.

In collaboration with NIAB TAG, the aim of this project was to investigate alternative methods to quantify and alleviate subsoil compaction in arable soils. Initially, the impact of long-term rotation and cultivation approach on subsoil compaction was investigated utilising the NIAB STAR field experiment (Suffolk, UK).

Subsequently, the potential of two cover crop species to alleviate subsoil compaction through root bio drilling was determined. Currently, work is being carried out to compare the ability of established field methods and remote sensing to characterise subsoil compaction in the field.

Key highlights to date include

• Long-term cover crop rotation had a positive impact improving subsoil structure and reducing subsoil compaction in the field
• In a single year, the bio drilling action of cover crop roots had a limited impact on subsoil compaction and crop performance
• Image analyses captured benefits of cover crop rotation to subsoil structure and compaction not observed using traditional field and laboratory methods

For more information, please contact Mr Joseph Martlew (joseph.martlew@cranfield.ac.uk) or Dr Lynda Deeks (l.k.deeks@cranfield.ac.uk).