Measuring Soil Compaction
📌 Soil compaction (not to be confused with surface firmness) is assessed using soil resistance/penetration tests, combined with visual and physical inspection of the soil profile.
🎯 Soil Penetration Resistance Testing
This measures deeper soil compaction, not just surface firmness.
Tools used
Penetrometer
Soil resistance probe
How it works
The device is pushed into the soil.
It measures the force needed to penetrate to various depths.
Assessment
Increased resistance at certain depths indicates compaction layers (pans), typically at:
75–100 mm
150–200 mm
Why it matters
A compacted layer restricts:
Rooting depth
Drainage
Oxygen movement
Water infiltration
🎯 Soil Profile Inspection (Core Samples)
A physical check of the profile is a crucial element of PQS assessment.
Tools used
Soil sampler / flat edged spade
Knife to investigate sample
What is checked
Compaction layers (visible tight, smeared, or horizontal bands)
Root depth and density
Layering between topdressing materials
Thatch or fibre build-up
Soil structure and porosity
Indicators of compaction in the soil
Dense, structureless soil
Shallow roots curtailed at a tight layer
Water sitting on a particular horizon
Little pore space or crumb structure
Ground Cover and Turf Health Indicators
Soil compaction may also present itself on the surface.
Thin or weak sward
Surface water after rain
Localised dry patch
Moss or algae growth