LOCATION MUCARA PR

Established Series
ASR; SRT; MMR
06/2022

MUCARA 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 basalt lava and breccia
Slope: 5 to 60 percent
Mean Annual Air Temperature: 25 degrees C. (77 degrees F.)
Mean Annual Precipitation: 1905 millimeters (75 inches)

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

TYPICAL PEDON: Mucara clay loam--naturalized pastureland (Colors are for moist soil).

Ap--0 to 15 centimeters (0 to 6 inches); very dark grayish brown (10YR 3/2) clay; weak fine granular structure; friable, slightly sticky, slightly plastic; many fine roots throughout; common fine tubular and common fine irregular pores; slightly acid; clear smooth boundary. (8 to 18 centimeters, 3 to 7 inches thick)

Bw--15 to 33 centimeters (6 to 13 inches); 50 percent dark yellowish brown (10YR 4/4) and 50 percent dark grayish brown (10YR 4/2) clay; weak medium subangular blocky structure; firm, slightly sticky, moderately plastic; common fine roots throughout; common fine irregular and common very fine irregular pores; 10 percent faint pressure faces on all faces of peds; neutral; clear smooth boundary. (Combined thickness of the Bw horizon ranges from 30 to 46 centimeters, 12 to 18 inches)

BC--33 to 48 centimeters (13 to 19 inches); 34 percent dark yellowish brown (10YR 4/4), 33 percent very dark grayish brown (10YR 3/2) and 33 percent light olive brown (2.5Y 5/4) clay loam; massive structure; friable, slightly sticky, slightly plastic; few fine roots throughout; common fine irregular and common very fine irregular pores; neutral; 20 percent, by volume of saprolite material; clear smooth boundary.

C--48 to 69 centimeters (19 to 27 inches); 40 percent olive brown (2.5Y 4/3), 30 percent light brownish gray (2.5Y 6/2), 30 percent light yellowish brown (2.5Y 6/4) and olive (5Y 4/3) saprolite material; friable; highly weathered volcanic rock; neutral; gradual wavy boundary.

Cr--69 to 94 centimeters (27 to 37 inches); slightly weathered, fractured and semiconsolidated volcanic bedrock.

TYPE LOCATION: Morovis, Puerto Rico. Approximately 49 feet south of paved road, 0.9 mile east of kilometer marker 0.5 of Highway 619; Cuchillas ward in naturalized pastureland. USGS Corozal topographic quadrangle (1966); lat. 18 degrees 18 minutes 41.8 seconds N.; long. 66 degrees 22 minutes 46.3 seconds W.

RANGE IN CHARACTERISTICS:
Solum thickness: Range from 25 to 50 centimeters (10 to 20 inches)
Depth to fractured volcanic bedrock: Ranges from 50 to 100 centimeters (20 to 40 inches)
Rock fragments: Range from 0 to 15 percent, by volume, throughout the profile
Content of pebbles range from 0 to 15 percent, by volume, throughout
Soil reaction: Strongly acid to slightly alkaline throughout

Range of Individual Horizons
A or Ap horizon:
Color - Hue of 5YR to 2.5Y, value of 2 to 5, and chroma of 2 to 4
Texture - Silty clay loam, silty clay, clay loam or clay in the fine-earth fraction.

Bw horizon:
Color - Hue of 7.5YR to 2.5Y, value of 3 to 6, and chroma of 2 to 6
Texture - Silty clay loam, loam, silt loam, clay loam, silty clay, or clay in the fine-earth fraction.

BC horizon: (where present)
Has color and texture similar to the Bw horizon with gravelly analogs

C horizon:
Color - Has no dominant color and is multicolored in shades of brown, yellow, and gray
The original rock structure is visible and weathered rock fragments can be easily broken between fingers. Low chroma mottles appear to have been inherited from the parent material and are not due to wetness.
Texture - Loam or silty clay loam.

The Cr horizon:
Composed of semi-consolidated and slightly weathered volcanic rock. It can be excavated with difficulty with hand tools and is rippable by mechanical equipment.

COMPETING SERIES: These are the Morado soils.
Morado soils--allow redder hues and have more clay in the control section.

GEOGRAPHIC SETTING:
Landscape: Hills and mountains on Humid Mountains and Valley, MLRA 270
Landform: Summits and side slopes of hills and mountains
Parent material: Residuum weathered from basalt lava and breccia
Mean Annual Air Temperature: 24 to 26 C. (75 to 79 degrees F.)
Mean Annual Precipitation: 1,092 to 1,854 millimeters (43 to 73 inches)

GEOGRAPHICALLY ASSOCIATED SOILS:
These include the Caguabo, Maraguez, and Quebrada series. All of these soils are on similar landscape positions.
Caguabo soils--are shallow to bedrock and have thinner Bw horizons.
Maraguez soils--are very deep and only allow 10YR hue.
Quebrada soils--have argillic horizons and are shallow to bedrock.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: Well drained
Saturated hydraulic conductivity (Ksat): Moderately high or high.

USE AND VEGETATION:
Major uses: Most areas of Mucara soils are on naturalized pastureland. Some small areas used for cash crops and coffee.
Dominant vegetation: Native and introduced grasses, shrubs, and trees.

DISTRIBUTION AND EXTENT:
Summits and side slopes of hills and mountains of the Humid Mountains and Valleys MLRA 270.
The series is of major extent.

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

SERIES ESTABLISHED: Soil Survey of Puerto Rico; 1942.

REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from 0 to 15 centimeters (0 to 6 inches, Ap horizon).
Cambic horizon - the zone from 15 to 33 centimeters (6 to 13 inches, Bw horizon).
Paralithic contact - the zone from 69 to 94 centimeters (27 to 37 inches, Cr horizon).

An SDJR / evaluation project modified the taxonomic classification Coarse-loamy, vermiculitic, isohyperthermic Dystric Eutrudepts to Fine-loamy, mixed, superactive, isohyperthermic Vertic Eutrudepts. The typical pedon was relocated to representative location of the MLRA 270.

National Cooperative Soil Survey
U.S.A.