Natural Resources
Conservation Service
Major Land Resource Area 102A
Major Land Resource Area
Accessed: 04/30/2026
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1
Select an ecological site
Select an ecological site using the list, keys, photos, briefcase, or quick search option located on this page. -
2
Explore the ecological site description
Next, learn more about the selected ecological site and its characteristic dynamics by browsing the ecological site description and exploring alternative state and transition model formats.
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Zoom in to display soil survey map units for an area of interest, and zoom out to display MLRAs. Select a map unit polygon to view ecological sites correlated to that map unit. View a brief description of an ecological site by clicking on its name in the map popup. Soil survey correlations may not be accurate, and ecological site classification of a location should always be verified in the field. Each selection may require the transfer of several hundred KB of data.
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Ecological sites
Major Land Resource Areas
Ecological site photos
Tools
Filter by
interactive key
precipitation
frost free days
more..
clear all
Type
Image size
Done
Filters
Interactive key
Precipitation
Frost free days
Elevation
Slope
Landform
Parent material kind
Soil texture
Key 1 of 4
Key 2 of 4
Key 3 of 4
Key 4 of 4
Dig a hole to a depth of 20 inches
Is it organic?
See MLRA Key "Other Landscape Positions"
Is there a root restricting layer within 10 inches of soil surface?
Very Shallow
R102AY016SD – Very Shallow
R102AY016SD – Very Shallow
Is there a root restricting layer within 10-20 inches of soil surface?
Gravel? (greater than 15% by volume)
Does the soil effervesce with acid (10% HCL) at or near (within 6 inches) the surface?
R102AY014SD – Shallow Gravel
Bedrock (siltstone, sandstone, mudstone, etc)?
Shallow Loamy
R102AY024SD – Shallow Loamy
R102AY024SD – Shallow Loamy
Thin Upland
R102AY012SD – Thin Upland
R102AY012SD – Thin Upland
See MLRA Key "Normal Landscape Positions"
Dig a hole to a depth of 20 inches
Is it Organic?
See MLRA Key "Other Landscape Positions"
Are there visible salts (including sodium and gypsum) within 16 inches or a claypan of the surface?
Is there a claypan (columnar structure) within 16 inches of the surface?
What is the surface and subsoil texture?
See MLRA Key "Other Landscape Positions"
Clay, Silty Clay (>40% clay) or Loamy Surface with Clayey subsoil
Clayey ... R102AY011SD
R102AY011SD – Clayey
R102AY011SD – Clayey
Loam, Silt loam, Silty clay loam, Clay loam, Sandy clay loam, very fine sandy loam
Loamy ... R102AY010SD
R102AY010SD – Loamy
R102AY010SD – Loamy
Sandy loam, Fine sandy loam, Loamy very fine sand
Sandy ... R102AY009SD
R102AY009SD – Sandy
R102AY009SD – Sandy
Sand, Loamy sand, Loamy fine sand
Sands ... R102AY008SD
R102AY008SD – Sands
R102AY008SD – Sands
Dig hole to a depth of 20 inches
Is it organic?
See MLRA Key "Other Landscape Positions"
Observe the soil profile to a depth of 60 inches.
Is there evidence of a permanent water table within 0-2 feet of the surface and the site dominated by hydrophytes?
Are there visible salts (including sodium and gypsum) within 16 inches of the surface?
Is there evidence of a permanent water table within 2 to 5 feet of the surface?
Saline Lowland ... R102AY007SD
R102AY007SD – Saline Lowland
R102AY007SD – Saline Lowland
Linear Meadow ... R102AY002SD
R102AY002SD – Linear Meadow
R102AY002SD – Linear Meadow
Does the soil effervesce with acid at or near the surface or have visible salt (including sodium and gypsum) crystals within 6 inches?
Does water flow into and over/through the site?
Subirrigated ... R102AY003SD
R102AY003SD – Subirrigated
R102AY003SD – Subirrigated
Salts within 16 inches?
Saline Subirrigated ... R102AY036SD
R102AY036SD – Saline Subirrigated
R102AY036SD – Saline Subirrigated
Limy Subirrigated ... R102AY006SD
R102AY006SD – Limy Subirrigated
R102AY006SD – Limy Subirrigated
See MLRA Key "Other Landscape Positions"
Does it have a flooding frequency?
Loamy Floodplain ... R102AY040SD
R102AY040SD – Loamy Floodplain
R102AY040SD – Loamy Floodplain
What is the surface texture of the soil?
Clay, Silty Clay
Clayey Overflow ... R102AY021SD
R102AY021SD – Clayey Overflow
R102AY021SD – Clayey Overflow
Loamy Overflow ... R102AY020SD
R102AY020SD – Loamy Overflow
R102AY020SD – Loamy Overflow
Dig hole to a depth of 20 inches
Is it organic?
Does the soil effervesce with acid (10% HCL) at or near (within 6 inches) the surface?
Does the soil have a claypan (columnar structure) within 16 inches?
Shallow Peatland
R102AY039SD – Shallow Peatland
R102AY039SD – Shallow Peatland
Calcareous Fen
R102AY038SD – Calcareous Fen
R102AY038SD – Calcareous Fen
Is the claypan within 6 inches of the surface
Is the area in a basin or closed depression with no outlet?
Not in MLRA 102A
Claypan
R102AY013SD – Claypan
R102AY013SD – Claypan
Re-think your position and start again!
Does the site pond water for 4 to 8 weeks in the spring or after heavy rain and have high organic matter content?
Wet Meadow
R102AY004SD – Wet Meadow
R102AY004SD – Wet Meadow
Does the site pond water until early summer and have high organic matter content?
Shallow Marsh
R102AY001SD – Shallow Marsh
R102AY001SD – Shallow Marsh
Does the site pond water year round in most years and have high organic matter content?
Deep Marsh
R102AY037SD – Deep Marsh
R102AY037SD – Deep Marsh
Long term average mean annual precipitation
- No filter
- 60 – 80cm (24 – 31in)
—
cm
Long term average frost free days
- No filter
- 110 – 130days
—
days
- No filter
- 200 – 400m (700 – 1300ft)
- 400 – 600m (1300 – 2000ft)
- 600 – 800m (2000 – 2600ft)
—
m
- No filter
- 0 – 3%
- 3 – 5%
- 5 – 10%
- 10 – 15%
- 15 – 20%
- 20 – 25%
- 25 – 30%
- 30 – 35%
- 35 – 40%
- 40 – 45%
—
%
- No filter
- Closed depression
- Depression
- Drainageway
- Flood plain
- Ground moraine
- Moraine
- Outwash plain
- Plain
- Pothole
- Swale
- Terrace
- No filter
- Alluvium
- Organic, unspecified
- Till, unspecified
Soil surface texture
- No filter
- Clay
- Clay loam
- Fine sandy loam
- Loam
- Loamy fine sand
- Loamy sand
- Loamy very fine sand
- Sand
- Silty clay
- Silty clay loam
- Silt loam
- Sandy loam
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Ecological site keys
RUN-OFF Landscape Positions (upland, normally convex short slopes)
A
Dig a hole to a depth of 20 inches
B.
Is it organic?
Yes
See MLRA Key "Other Landscape Positions"
No
Is there a root restricting layer within 10 inches of soil surface?
No
Is there a root restricting layer within 10-20 inches of soil surface?
Yes
Gravel? (greater than 15% by volume)
Yes
... R102AY014SD – Shallow Gravel
No
Bedrock (siltstone, sandstone, mudstone, etc)?
No
Does the soil effervesce with acid (10% HCL) at or near (within 6 inches) the surface?
No
See MLRA Key "Normal Landscape Positions"
NORMAL Landscape Positions (Upland, slopes normally linear, except sandy/sands sites can have complex slopes)
A.
Dig a hole to a depth of 20 inches
B.
Is it Organic?
Yes
See MLRA Key "Other Landscape Positions"
No
Are there visible salts (including sodium and gypsum) within 16 inches or a claypan of the surface?
Yes
Is there a claypan (columnar structure) within 16 inches of the surface?
Yes
See MLRA Key "Other Landscape Positions"
No
What is the surface and subsoil texture?
C.
Clay, Silty Clay (>40% clay) or Loamy Surface with Clayey subsoil
No
Loam, Silt loam, Silty clay loam, Clay loam, Sandy clay loam, very fine sandy loam
No
Sandy loam, Fine sandy loam, Loamy very fine sand
No
Sand, Loamy sand, Loamy fine sand
RUN-IN Landscape Positions (Floodplain, Drainageways, etc., except depressions)
A.
Dig hole to a depth of 20 inches
B.
Is it organic?
Yes
See MLRA Key "Other Landscape Positions"
No
Observe the soil profile to a depth of 60 inches.
C.
Is there evidence of a permanent water table within 0-2 feet of the surface and the site dominated by hydrophytes?
Yes
Are there visible salts (including sodium and gypsum) within 16 inches of the surface?
No
Is there evidence of a permanent water table within 2 to 5 feet of the surface?
Yes
Does the soil effervesce with acid at or near the surface or have visible salt (including sodium and gypsum) crystals within 6 inches?
Yes
Salts within 16 inches?
No
Does water flow into and over/through the site?
No
See MLRA Key "Other Landscape Positions"
Yes
Does it have a flooding frequency?
No
What is the surface texture of the soil?
D.
Clay, Silty Clay
OTHER Landscape Positions (Basin, Depression, Run-off and/or Run-in)
A.
Dig hole to a depth of 20 inches
B.
Is it organic?
Yes
Does the soil effervesce with acid (10% HCL) at or near (within 6 inches) the surface?
No
Does the soil have a claypan (columnar structure) within 16 inches?
Yes
Is the claypan within 6 inches of the surface
Yes
Not in MLRA 102A
No
Is the area in a basin or closed depression with no outlet?
No
Re-think your position and start again!
Yes
Does the site pond water for 4 to 8 weeks in the spring or after heavy rain and have high organic matter content?
No
Does the site pond water until early summer and have high organic matter content?
No
Does the site pond water year round in most years and have high organic matter content?
The Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
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