LOCATION MORADO PR

Established Series
SRT/MMR/AMA
06/2022

MORADO SERIES

MLRA(s): 270
MLRA Soil Survey Regional Office (SSRO) Responsible: Raleigh, North Carolina
Depth Class: Moderately deep
Drainage Class: Well drained
Saturated Hydraulic Conductivity: Moderately high to high
Parent Material: Residuum weathered from volcanic rock.
Slope: 12 to 60 percent
Mean Annual Air Temperature: 25 degrees C. (77 degrees F.)
Mean Annual Precipitation: 2,006 millimeters (79 inches)

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, isohyperthermic Dystric Eutrudepts

TYPICAL PEDON: Morado clay loam--pigeon peas (Colors are for moist soil)

Ap--0 to 18 centimeters (0 to 7 inches); dark reddish gray (10R 4/1) clay loam; weak fine subangular blocky structure; friable, slightly sticky, moderately plastic; low excavation difficulty; common fine roots; neutral; clear smooth boundary.

Bw--18 to 43 centimeters ( 7 to 17 inches); reddish gray (5YR 5/2) clay loam; few fine faint yellowish red (5YR 5/6), reddish brown (2.5YR 5/3) and weak red (10R 5/3) mottles; weak fine granular structure and weak fine subangular blocky structure; friable, slightly sticky, moderately plastic; low excavation difficulty; common fine roots; slightly acid; approximately 5 percent of highly weathered saprolite material with the following colors weak red (2.5YR 4/2); yellowish red (5YR 4/6) and reddish brown (5YR 4/3); gradual wavy boundary.

BC--43 to 61 centimeters (17 to 24 inches); variegated brown (7.5YR 4/2), dark gray (5YR 4/1) and dark reddish gray (5YR 4/2) loam; weak fine subangular blocky structure; friable, slightly sticky, moderately plastic; low excavation difficulty; common fine roots; slightly acid; approximately 30 percent of highly weathered saprolite material with the following colors weak red (2.5YR 4/2); yellowish red (5YR 4/6) and reddish brown 5YR 4/3; clear wavy boundary.

C--61 to 84 centimeters (24 to 33 inches); variegated gray (5YR 5/1), dark reddish gray (5YR 4/2) and brown (7.5YR 4/2) loam; massive structureless; friable, nonsticky, slightly plastic; low excavation difficulty; slightly acid; this horizon consist of highly weathered saprolite material with visible rock structure; low excavation difficulty and rippable with hand tools; clear wavy boundary.

R--84 centimeters (33 inches); reddish gray (5YR 5/2) semi-consolidated volcanic rock; very high excavation difficulty.

TYPE LOCATION: Mayaguez, Puerto Rico, 6.5 miles northeast of the city of Mayaguez, 1,640 feet on dirt road for kilometer marker 3.85 on Highway No. 406 and 66 feet north of dirt road. Central La Plata Quadrangle, Puerto Rico (1964). Latitude: 18 degrees 16 minutes 29 seconds north, Longitude: 67 degrees 04 minutes 28 seconds west WGS 84.

RANGE IN CHARACTERISTICS:
Thickness of the solum ranges: from 25 to 76 centimeters (10 to 30 inches).
Depth to the semi-consolidated volcanic rock range: from 50 to 100 centimeters (20 to 40 inches).
Soil Reaction: Moderately acid to neutral throughout.

Range of Individual Horizons:
A or Ap horizon:
Color - Hue of 10R to 7.5YR, value of 3 to 6, and chroma of 1 or 2
Texture - clay loam, silty clay loam, loam, or clay
Content of paragravels is less than 5 percent, by volume

Bw horizon:
Color - hue of 2.5YR to 7.5YR, value of 3 to 5, and chroma of 1 to 6
Texture - clay loam, silty clay loam, loam or clay
Masses of former rock fragments from parent material occur as shades of yellow, red, and brown range from none to common. These colors are derived from the parent material and are not indicative of wetness.
Content of paragravels ranges from 0 to 25 percent, by volume
Content of saprolite ranges from 5 to 10 percent, by volume

BC horizon:
Color - Hue of 5YR or 7.5YR, value of 3 or 4, and chroma 1 or 2; or has no dominant color and is multicolored in shades of red, brown, yellow and gray. These colors are derived from the parent material and are not indicative of wetness
Texture - silty clay loam, loam, silt loam, or clay loam
Content of paragravels ranges from 0 to 15 percent, by volume
Content of saprolite ranges from 20 to 40 percent, by volume

C horizon:
Color - has no dominant color and is multicolored in shades of red, brown, yellow and gray
Texture - loam or silty clay loam, clay loam, or silt loam
Original rock structure is visible and weathered rock fragments can be easily broken between fingers
Low chroma colors are inherited from the parent material and are not associated with soil wetness
Content of paragravels ranges from 0 to 15 percent, by volume

Cr horizon (if present):
Is composed of highly fractured and moderately weathered volcanic rock
It can be excavated with difficulty with hand tools, and is rippable by mechanical equipment

R horizon:
Is composed of hard, semi-consolidated volcanic bedrock

COMPETING SERIES:
Mucara soils--are similar to Morado but have hues yellower and are slightly coarser in texture

GEOGRAPHIC SETTING:
Landscape: Humid Mountains and Valleys of Puerto Rico (MLRA 270).
Landform: Morado soils are on summits and side slopes
Parent Material: Residuum weathered from volcanic rock.
Mean Annual Air Temperature: 24 to 26 degrees C. (75 to 79 degrees F).
Mean Annual Precipitation: 1,270 to 2,032 millimeters (50 to 80 inches).

GEOGRAPHICALLY ASSOCIATED SOILS:
These include the Caguabo, Maraguez, and Quebrada series.
- Caguabo soils--are shallow to bedrock
Maraguez soils--are very deep to bedrock and allow only 10YR hue throughout
- Quebrada soils--are very deep and have argillic horizons

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: Well drained
Saturated Hydraulic Conductivity: Moderately high to high.

USE AND VEGETATION:
Most areas of Morado soils are on naturalized pastureland. Some small areas used for pigeon peas plantation. The vegetation consists of native and introduced grasses, shrubs, and trees.

DISTRIBUTION AND EXTENT:
Summits and side slopes of the Humid Mountains and Valleys MLRA 270 in Puerto Rico.
-The series is of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Raleigh, North Carolina.

SERIES ESTABLISHED: Ponce Soil Survey Area, Puerto Rico; 1971.

REMARKS:
The 2014 update changes the particle size class back to fine-loamy from fine. Data indicates it should never have been fine.
Diagnostic horizons and features recognized in this pedon:
1. Ochric epipedon - the zone from 0 to 18 centimeters (0 to 7 inches) (Ap horizon).
2. Cambic horizon - the zone from 18 to 43 centimeters (7 to 17 inches) (Bw horizon).
3. Lithic contact - 84 centimeters (33 inches).

ADDITIONAL DATA:
Characterization data - pedon No. S1961PR011003; sample by KSSL, Lincoln NE.

National Cooperative Soil Survey
U.S.A.