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Problem Hydric Soils

Problem Hydric Soils. Saturated, but not Reduced. Low organic matter e.g., sands No iron e.g., E horizons of Spodosols, sands Oxygenated water slopes, sands and gravels, “perched” water tables Cold temperatures High pH, salinity. Problem Hydric Soils. Dark A horizons > 12” thick

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Problem Hydric Soils

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  1. Problem Hydric Soils

  2. Saturated, but not Reduced • Low organic matter • e.g., sands • No iron • e.g., E horizons of Spodosols, sands • Oxygenated water • slopes, sands and gravels, “perched” water tables • Cold temperatures • High pH, salinity

  3. Problem Hydric Soils • Dark A horizons > 12” thick • Mostly Mollisols (Mollic epipedons) • Dark colors from high OM mask redox features • Thick, sandy E horizons • Most often Spodosols • Lack of Fe in E horizon • Soils with little development • Usually Entisols • Sandy soils, low OM, recent deposits on floodplains

  4. Problem Hydric Soils • Heavy clay soils • Most are Vertisols or Vertic subgroups • Dark colors from high OM mask redox features in surface layers • Constant churning of soils may disrupt features and/or gray colors • Soils with perched water tables and bright subsoils

  5. Problem Hydric Soils • Parent materials • Reddish colored • e.g., materials derived from Mesozoic sediments • Gray colored • e.g., lacustrine and marine deposits • Dark colored • e.g., Carboniferous material

  6. Approaches for Delineating Problem Hydric Soils • Field Indicators of Hydric Soil in the United States’ regionally specific indicators for problem soils. • Observations made along a hydrologic gradient. • Research and local soil scientist’s knowledge of problem soils. • Hydric soils lists.

  7. Landscape Transect Approach • Soils occur as a continuum on the landscape • Describe a known “wet” soil • Describe a known “upland” soil • Use judgment to discern the boundary Wettest Wet ??? Upland

  8. Beware of lithochromic mottles

  9. Be cautious of reduce matrices • If a soil is saturated at the time of excavation, make sure you do soil colors as you dig the soil. Reduced matrices will change color upon exposure to air. Therefore, if you wait to do soil colors, you may not get the colors you expect.

  10. Which soil is the hydric soil?

  11. Which soil is the hydric soil? Hydric soil in marl. Note the organic streaking. Upland soil in Marl.

  12. Which soil is the hydric soils?

  13. Which soil is the hydric soils? Sandy hydric soil with thick dark surface and yellow sands underneath. Sandy upland soil with a thick E horizon.

  14. Which soil is the hydric soil?

  15. Which soil is the hydric soil? Hydric soil with a reduced matrix that has brightened upon exposure to oxygen. Upland gray parent material soil.

  16. Red Parent Material

  17. Redox depletions along ped faces

  18. F3 in Red Parent Material

  19. Relict features in red parent material

  20. Glauconitic upland soil that meets F6

  21. Wet soil containing glauconite

  22. Graphitic phyllite parent material

  23. Gray bedrock

  24. Latort profile

  25. Diatamaceous earth

  26. Gray E horizon in a coarse loamy upland soil

  27. “Dirty” E horizon in a wet spodosol

  28. “ABLS” soil found in freshwater wetlands adjacent to tidal areas

  29. “ABSS”

  30. Piedmont floodplains

  31. Buried hydric soil on Piedmont floodplains

  32. High pH/High Salt/High Gypsum

  33. Still not sure? • Landscape position, landscape position… • compare soil profiles from various landscape positions • Look at the entire soil profile • top to bottom, not just 10” or immediately below the A • Indicators of wetland hydrology and a hydrophytic plant community • herbaceous layer is often more diagnostic than trees • When all else fails....

  34. … MONITOR !!

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