Science · Soils
Clay
Fine particles under 0.002 mm that hold large amounts of water and nutrients but drain poorly and shrink-swell.
Soil texture class
Profile
- Particle size
- < 0.002 mm
- Drainage
- Very slow
- Water holding
- Very high (much unavailable)
- CEC
- Very high
Water & soil targets
- Moisture (VWC)
- Field capacity ~38–46%; wilting point ~20–28%
- Salinity tolerance
- Salts accumulate; sodic risk
- Drought tolerance
- Cracks when dry
Plants can wilt even with high moisture readings because much water is bound.
Problems to watch
- Waterlogging
- Compaction
- Shrink–swell cracking
- Sodicity
Stress signs
- Surface cracks
- Ponding
- Yellowing from low oxygen
Where you'll find it
- Native urban soils
- Agricultural valleys
More soils
All Science profilesGeneral agronomic guidance and typical ranges; actual targets vary by site, soil, climate and season.