Science · Soils
Claypan
Dense clay-enriched layer that can restrict water movement and root penetration.
Restrictive soil horizon
Profile
- Position
- Often subsurface beneath a different topsoil
- Flow
- Can create seasonal perched water
- Roots
- Roots may concentrate above the layer
- Diagnosis
- Distinguish a natural claypan from a traffic pan
Water & soil targets
- Moisture (VWC)
- Site-calibrated; measure field capacity and dry-down
- Salinity tolerance
- Not determined by this label; measure EC and relevant ions
- Drought tolerance
- Depends on usable storage, rooting depth and vegetation
Measure retention, infiltration and layer depths in place. Texture or construction labels do not define a universal irrigation threshold.
Problems to watch
- Seasonal saturation
- Shallow rooting
- Erosion from runoff
Stress signs
- Wet upper profile
- Roots turning laterally
- Runoff after rain
Where you'll find it
- Drainage assessment
- Root-zone limitation mapping
More soils
All Science profilesGeneral agronomic guidance and typical ranges; actual targets vary by site, soil, climate and season.