1. Anomalous Bright Loamy Soils: Newly Recognized Hydric Soils in the Mid Atlantic Coastal Plain
Martin C. Rabenhorst
University of Maryland
Dept. of Environmental Science and Technology
College Park, MD

2. From FIHSUS
Hydric Soils: “that formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part” (Federal Register, July 13, 1994).
Nearly all hydric soils exhibit characteristic morphologies that result from repeated periods of saturation and/or inundation for more than a few days. This anaerobiosis promotes biogeochemical processes, such as
the accumulation of organic matter and
the reduction, translocation, and/or accumulation of iron and other reducible elements.
These processes result in characteristic morphologies …. making them particularly useful for identifying hydric soils.

4. Typical “Hydric” Soil Organic matter accumulation
Depletion of iron oxides from the matrix
Segregation of iron oxides into prominent concentrations

5. The Problem
Soils identified that meet saturation and reduction requirements for hydric soils
But they do not show the typical morphological features of hydric soils

6. Anomalous Bright Loamy Soils ABLS
Not dominantly gray
Loamy in texture (loams and silt loams)
Anomalous Bright Loamy Soils ABLS

7. Anecdotal observations led to a research study
M.S. Thesis of Philip K. Zurheide
Under the guidance of the Mid-Atlantic Hydric Soils Committee

8. Research hypotheses for the explanation of the ABLS phenomenon
Soils not saturated long enough
Oxyaquic conditions (saturated by not reducing)
Parent materials inherently resistant to color change (analogous to TF2 – red parent material)
Low lateral hydraulic gradient – sea level rise *

9. F20. Anomalous Bright Loamy Soils.
For use in MLRA 149A of LRR S and MLRAs 153C and 153D of LRR T; for testing in MLRA 153B of LRR T.
Within 200 m (656 feet) of estuarine marshes or waters and within 1 m (3.28 feet) of mean high water,
a mineral layer at least 10 cm (4 inches) thick starting within 20 cm (8 inches) of the soil surface
with a matrix (60 percent or more of the volume) chroma of less than 5 and 10 percent or more distinct or prominent redox concentrations occurring as soft masses or pore linings and/or depletions.
User Notes: These soils are expected to occur on linear or convex landforms that are adjacent to estuarine marshes or waters.

10. For use in MLRA 149A of LRR S and MLRAs 153C and 153D of LRR T

11. for testing in MLRA 153B of LRR T

12. Eastern Neck Island NWR
160 m
Within 200 m (656 feet) of estuarine marshes or waters and within 1 m (3.28 feet) of mean high water,

13. A mineral layer at least 10 cm (4 inches) thick starting within 20 cm (8 inches) of the soil surface
Can be overlain by any material

14. matrix (60 percent or more of the volume) chroma of less than 5 (closer to 4 than to 6)
10 percent or more distinct or prominent redox concentrations occurring as soft masses or pore linings and/or depletions.

15. Eastern Neck Island A AE BE Bt1 Bt2
a layer at least 10 cm (4 inches) thick
starting within 20 cm (8 inches) of the soil surface
with a matrix chroma of less than 5
10 percent or more distinct or prominent redox
concentrations and/or depletions
10YR 3/1
10YR 4/3
2.5Y 5/4 with 30% 10YR 5/6 concentrations
7.5YR 5/6 with 30% 10YR 5/8 concentrations
20% 2.5 6/4 and 10% 2.5Y 6/3 depletions A AE BE
Bt1
Bt2

16. EN low A EA BE Bt1 a layer at least 10 cm (4 inches) thick
starting within 20 cm (8 inches) of the soil surface
with a matrix chroma of less than 5
10 percent or more distinct or prominent redox
concentrations and/or depletions
10YR 3/1
10YR 4/3 1% 7.5YR 4/6 concentrations
2.5Y 6/4 matrix
5-10% 10YR 5/8; 10% 10YR 4/6 concentrations
25% 2.5Y 6/3 depletions A EA BE
Bt1

17. BW high A AE Bt1 Bt2 a layer at least 10 cm (4 inches) thick
starting within 20 cm (8 inches) of the soil surface
with a matrix chroma of less than 5
10 percent or more distinct or prominent redox
concentrations and/or depletions
10YR 3.5/2 3% 7.5YR 3/3 concentrations
2.5Y 4/ % 7.5YR 3/3 concentrations
2.5Y 5/4 matrix
7% 7.5YR 4/6; 3% 7.5YR 3/4 concentrations
5% 2.5Y 5/3.2; 5% 2.5Y 6/2 depletions A AE
Bt1
Bt2

18. IOW high A AB BA Bt1 a layer at least 10 cm (4 inches) thick
starting within 20 cm (8 inches) of the soil surface
with a matrix chroma of less than 5
10 percent or more distinct or prominent redox
concentrations and/or depletions
7.5YR 3/2
10YR 4/3 10% 7.5YR 4/6; 5% 5YR 3/4 concentrations
3% 2.5Y 4/2 depletions
2.5Y 5/4 35% 10YR 5/6; 3% 7.5YR 4/6 concentrations A AB BA
Bt1

19. TH low a layer at least 10 cm (4 inches) thick
starting within 20 cm (8 inches) of the soil surface
with a matrix chroma of less than 5
10 percent or more distinct or prominent redox
concentrations and/or depletions
7.5YR 2.5/ % 5YR 3/3 pore linings
7.5YR 2/ % 5YR 3/3 pore linings
2.5Y 3/ % 7.5YR 3/4 pore linings A1 A2 AE EB Bt

20. ABLS An indicator now approved to accommodate these problem soils.
Should be kept in mind when examining low elevation soils on the coastal plain within 200 meters of tidal water or tidal marsh

21. We would like to express appreciation to the following organizations who helped to support this work:
Maryland Department of the Environment
US Environmental Protection Agency
Maryland Agricultural Experiment Station
Mid-Atlantic Hydric Soil Committee