Science · Soils
Ultisol
Strongly weathered soils with clay-enriched subsurface horizons and low base saturation.
USDA Soil Taxonomy order
Profile
- Diagnostic
- Argillic or kandic horizon with low base status
- Chemistry
- Acidity and aluminum toxicity can constrain sensitive plants
- Texture
- Surface textures vary
- Nutrients
- Liming and fertilizer require soil-test guidance
Water & soil targets
- Moisture (VWC)
- Site-calibrated; measure field capacity and dry-down
- Salinity tolerance
- Not inferable from soil classification; test EC, sodicity and water chemistry
- Drought tolerance
- Not inferable from taxonomy; measure accessible storage and plant response
Soil orders and WRB groups are not textures. Determine horizon-specific retention, field capacity, drainage, rooting depth and seasonal hydrology before setting irrigation triggers.
Problems to watch
- Acidity-related root restriction
- Phosphorus limitation
- Erosion
Stress signs
- Stunted roots
- Poor growth
- Exposed clay subsoil
Where you'll find it
- Acid-soil planting plans
- Nutrient and lime planning
More soils
All Science profilesGeneral agronomic guidance and typical ranges; actual targets vary by site, soil, climate and season.