LOCATION MACHETE PREstablished Series
The Machete series is a member of the fine, mixed, isohyperthermic family of Typic Haplustalfs. These soils have reddish brown, granular, strongly acid A horizons; yellowish red, fine textured, acid B horizons over coarser textured C horizons.
TAXONOMIC CLASS: Very-fine, mixed, active, isohyperthermic Aridic Paleustalfs
TYPICAL PEDON: Machete loam - sugar cane
(Colors are for moist soil.)
Ap--0 to 9 inches; reddish-brown (5YR 4/3) loam; weak fine granular structure; very friable; many fine roots; few fine black concretions; common fine sand grains; strongly acid; clear smooth boundary. (7 to 14 inches thick)
A12--9 to 14 inches; reddish-brown (5YR 4/3) loam; weak fine granular structure; very friable; few fine roots; common medium and fine pores; common fine sand grains; strongly acid; clear smooth boundary. (3 to 10 inches thick)
B1--14 to 20 inches; reddish-brown (5YR 4/4) clay loam; weak medium subangular blocky structure; friable, slightly sticky, slightly plastic; few fine roots; common medium and fine pores; thin patchy clay films; few fine black concretions; many fine sand grains; strongly acid; clear smooth boundary. (4 to 12 inches thick)
B2t--20 to 32 inches; yellowish red (5YR 4/6) clay; moderate medium subangular blocky structure; firm, slightly sticky, plastic; thin discontinuous clay films, more numerous on vertical ped faces and in root channels than on horizontal ped faces; few worm casts; few black concretions; many sand grains; strongly acid; clear smooth boundary. (8 to 14 inches thick)
B3--32 to 39 inches; reddish-brown (5YR 4/4) sandy clay loam; weak medium subangular blocky structure; friable, slightly sticky, slightly plastic; few thin patchy clay films on peds and in root channels; few black concretions; many sand grains; few subrounded pebbles; strongly acid; abrupt smooth boundary. (5 to 12 inches thick)
IIC1--39 to 45 inches; reddish-brown (5YR 4/3) gravelly sandy clay loam; structureless, massive; friable; strongly acid; abrupt smooth boundary. (4 to 12 inches thick)
IIIC2--45 to 60 inches plus; dark brown (7.5YR 4/4) loamy sand; structureless, massive; very friable; strongly acid.
TYPE LOCATION: Arroyo, Puerto Rico; 1,000 feet east of Lafayette Sugar Central (Irrigation Reservoir) and 200 feet south of reservoir, 40 feet east of trail.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 27 to 62 inches. Soil reaction varies from very strongly to strongly acid. Mean annual soil temperature at 20 inches is 72 degrees F. or more and the difference between mean summer and mean winter temperatures is less than 9 degrees F. Mineralogy is mixed. Base saturation (by sum of cations) is 35 percent or more at 50 inches below the top of the argillic horizons. These soils are dry for 90 cumulative days or more during most years.
Colors of the surface horizons are in hues of 5YR and 7.5YR, values of 4 and chromas of 2 to 4. Texture of the surface layers ranges from sandy loam to clay loam.
Colors of the B horizons are in hues of 7.5YR and 5YR, values of 4 to 6 and chromas of 4 to 8. Structure of the B2t horizons range from weak to moderate subangular blocky. Dark concretions range from few to common and from fine to medium in size in the B horizons. The B3 horizons range from clay loam to sandy clay loam in texture.
C horizons are stratified gravelly sandy clay loams to loamy sands.
COMPETING SERIES: These are the Amelia, Bexar, Katemcy, Lindy, Guayama, Lavallee and Dorothea series. The Amelia soils have more than 35 percent coarse fragments in their argillic horizons. The Bexar, Katemcy and Lindy soils have thermic soil temperatures. The Guayama soils have hard rock within 20 inches of the surface. The Lavallee soils have coarser textured argillic horizons with less than 35 percent clay. The Dorothea soils have yellower B horizons in hues of 10YR and are less acid-neutral to medium acid.
GEOGRAPHIC SETTING: The Machete soils are on nearly level to gently sloping terraces and alluvial fans on the Coastal Plain. Slopes range from 0 to 5 percent. The regolith is moderately coarse to fine textured sediments derived from volcanic rocks. The climate is semiarid. Rainfall ranges form 30 to 45 inches and the average mean annual temperature is 80 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are in the Fraternidad, San Anton and Vives series. The Fraternidad soils are finer textured, dark colored, and calcareous. The Vives soils have darker colored A horizons and are neutral to mildly alkaline in reaction. The San Anton soils formed in recent sediments on flood plains have finer texture in the A horizon and are neutral to mildly alkaline in reaction.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium. Permeability is moderate.
USE AND VEGETATION: Most of the soil is cultivated and used for growing sugar cane, under irrigation.
DISTRIBUTION AND EXTENT: Semiarid coastal plains of Puerto Rico. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina
SERIES ESTABLISHED: Soil Survey of Puerto Rico, l942.
REMARKS: The Machete series was formerly classified in the Red-Yellow Podzolic great soil group.