Soil pH ©BONAP | 
Acid soils with pH < 6 ©BONAP | 
Neutral soils with pH 6-7. ©BONAP |
Basic soils with pH > 7. ©BONAP | 
Serpentine and ultramafic soils and/or possible outcrops ©BONAP
|  Concentration of wetlands and open water areas ©BONAP
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Wetland soils with nutrient-rich clays ©BONAP | 
Volcanic wetland soils ©BONAP
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Undeveloped wetland soils ©BONAP |
Weakly developed wetland soils ©BONAP
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Shrink/swell clay wetland soils ©BONAP
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Pine forest wetland soils ©BONAP
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Prairie wetland soils ©BONAP | 
Wetland soils with nutrient poor clays ©BONAP
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Undeveloped soils (excluding wetlands, fluvents, and psamnents) ©BONAP
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Acidic organic wetland soil ©BONAP
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Non-acidic organic wetland soil ©BONAP | 
Upland acidic sands ©BONAP |
Upland acidic clays ©BONAP | 
Upland acidic silts/loams ©BONAP | 
Upland acidic shallow ©BONAP |
Upland non-acidic clays ©BONAP | 
Upland non-acidic shallow soils ©BONAP | 
Excessively drained soils ©BONAP |
Well-drained soils ©BONAP | 
Very poorly-drained soils ©BONAP
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Soils with nutrient-rich clays (excluding wetlands) ©BONAP |
Volcanic soils (excluding wetlands) ©BONAP | 
Gypsum soils ©BONAP | 
Organic soils (excluding uplands) ©BONAP
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Mineral soils with high organic contect (excluding prairie soils) ©BONAP
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Mineral soils with high organic content ©BONAP | 
Deep sandy soil ©BONAP |
Limestone praire soils ©BONAP | 
Salty soils (high electric conductivity) ©BONAP | 
Soils with nutrient-poor clays (excluding wetlands) ©BONAP
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 Shrink/swell clay soils (excluding wetlands) ©BONAP |  Desert soils (excluding salt flats and gypsum) ©BONAP | 
Non-wetland floodplain soils ©BONAP |
 Various soils with elements of a floodplain soil ©BONAP |  Upland organic soils ©BONAP | 
Prairie soils (excluding wetlands) ©BONAP |
Salt flats ©BONAP | 
Pine forest soils (excluding wetlands) ©BONAP | 
Rock outcrops ©BONAP
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 Weakly developed soils (excluding wetlands) ©BONAP |  Shallow soils (bedrock within a half meter of the surface) ©BONAP | 
Man-made/modified soils ©BONAP |
 Relative soil moisture based on average drainage and climate ©BONAP | 
Soils of the lower 48 US states, based on dominant soil pH, textures, and wetland status (data from NRCS) ©BONAP | 
Soil orders and selected suborders of the United States, based on Soil Taxonomy of the USDA NRCS ©BONAP |
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