Soil type characteristics:
Vertisols occur dominantly in level landscapes under climates with a pronounced dry season. Vast areas are found in Australia, India, northeastern Africa (Sudan, Ethiopia), southern Latin America and the USA.
Characteristics
Soils having a vertic horizon (a clayey subsurface horizon with polished and grooved ped surfaces ("slickensides") or wedge-shaped or parallelepiped structural aggregates) within 100 cm from the soil surface. They have 30 percent or more clay in all horizons to a depth of 100 cm or more, or to a contrasting layer (lithic or paralithic contact, petrocalcic, petroduric or petrogypsic horizons, sedimentary discontinuity, etc.) between 50 and 100 cm, after the upper 20 cm have been mixed. In addition, Vertisols exhibit wide cracks, which open and close periodically.
Distribution of Vertisols (rough estimation supplied by soilgrids)
Description:
Reference soil CU021: Vertisols
Short field description: Deep, imperfectly drained, yellowish brown clay. Large cracks when dry, moderately, (sub)angular blocky structure, presence of calcareous conglomerates. Third and fourth horizon are very hard. The inclusions in the first and second horizon are gravels. Geology: mid-lower Miocene, clays, sands, marls, limestones and conglomerate. Geomorphology: marine plain and terrace, abrasive, slightly undulating and plain.
General information:
| Location | Provincia Holguín, Municipio Mayarí, CAI "Guatemala", area 3 |
| Köppen | As |
| Authors | Marín R, R Chang & B Montero |
| Date | 1991-12-01 |
| Lat/Lon | 20.6667, -75.8333 |
Code:
CU021
Parent material
| Kind 1 (parent material) ; Parker (eds), 1984 | claystone |
| Texture of parent material | clayey |
| Mode of accumulation or deposition of parent material | marine sediments |
| Remarks on Parent Materials | Mid-early Miocene clays, sands, marl, limestone and conglomerate |
| Soil Depth | 100cm |
Physiography
| Altitude | 20m |
| Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne. | low hill |
| Slope | 2% |
| Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006) | undulating |
| Form of the slope surrounding the site | undulating |
| Physiographic position of the site | flat |
| Physiographic Unit | undulating |
Hydrology and drainage
| Wet From To | 0-150cm |
| Drainage class ; FAO (2006) - Guidelines for soil description | imperfect |
| Estimated run off (class) | medium |
| Depth to groundwater table | 300cm |
| Flooding frequency (FAO, 1986) | never |
| Kind of ground water table (USDA, 1979) | groundwater table observed |
| Estimated permeability (class) of least permeable part of the profile | slow |
| Lower limit of a slow permeable or stagnating layer in the profile | 150cm |
| Upper limit of a slow permeable or stagnating layer in the profile | 120cm |
Erosion and degradation
| Intensity of the soil erosion type | slight |
| Slope stability | stable |
| Soil erosion type | rill |
Land use
| Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006) | shrub |
| Land use or vegetation in the immediate vicinity of the site | high level arable farming |
| Major crops | sugar cane |
| Status of vegetation; Guidelines for soil description - Fourth edition (FAO, Rome, 2006) | degraded |
Surface characteristics
| Average size of stone | 4 |
| Evidence of alkali ; Soil Survey Manual USDA, 1951 | moderately alkaline |
| Surface cracking | large cracks (width more than 1 cm, or depth more than 50 cm) |
| Evidence of salt; Soil Survey Manual USDA, 1951 | slightly saline |
| Surface stoniness class (FAO (2006) - Guidelines for soil description) | very few stones |
Classification
WRB 2006
| Sodic Stagnic Calcic Vertisols (Manganiferric ) |
| 27-95 | vertic horizon |
| 27-95 | calcic horizon |
WRB 1998
| Calcic Hyposodi Vertisols |
| 27-95 cm | vertic horizon |
| 27-95 cm | ferric horizon |
| 0-27 cm | ochric horizon |
FAO-UNESCO-ISRIC 1974
| Chromic Vertisols sodic |
| - | ferric horizon |
| - | slickensides horizon |
| - | vertic horizon |
| 0-27 cm | ochric A horizon |
| 27-95 cm | calcic / cambic B horizon |
Local classification
| Classification information | Oscuro plastico gleysoso gris |
Other classification
| USDA-NRCS (1999) | Sodic Haplustert |
| USDA-SCS (1975) | Sodic Chromustert ustic clayey montmorillonitic isohyperthermic |
Other
| Description of a site | Short field description: Deep, imperfectly drained, yellowish brown clay. Large cracks when dry, moderately, (sub)angular blocky structure, presence of calcareous conglomerates. Third and fourth horizon are very hard. The inclusions in the first and second horizon are gravels. Geology: mid-lower Miocene, clays, sands, marls, limestones and conglomerate. Geomorphology: marine plain and terrace, abrasive, slightly undulating and plain. |
Climate data
| Description | record | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Act. Evapotranspiration (mm) | 21 | 126 | 142 | 204 | 213 | 207 | 196 | 232 | 226 | 184 | 156 | 124 | 117 | 2127 |
| Bright sunshine (hours/day) | 10 | 7.5 | 7.7 | 8.7 | 9.1 | 7.9 | 7.9 | 8.3 | 8.2 | 7.5 | 7.6 | 7.5 | 7.6 | 8 |
| Epot. - Penman (mm) | 21 | 87 | 95 | 138 | 150 | 151 | 148 | 167 | 160 | 136 | 121 | 98 | 88 | 1539 |
| Maximum temperature (°C) | 21 | 28 | 28.4 | 29.3 | 30 | 31.1 | 32.1 | 32.5 | 32.8 | 32.6 | 31.6 | 29.8 | 28.5 | 30.6 |
| Mean temperature (°C) | 21 | 22.3 | 22.4 | 23.4 | 24.4 | 25.6 | 26.8 | 27.3 | 27.1 | 26.9 | 25.9 | 24.7 | 23.3 | 25 |
| Minimum temperature (°C) | 21 | 19.4 | 19.1 | 20.2 | 21 | 22.2 | 23.1 | 23.6 | 23.4 | 23 | 22.4 | 21.6 | 20.2 | 21.6 |
| Precipitation (mm) | 21 | 62 | 53 | 61 | 87 | 116 | 91 | 38 | 75 | 88 | 118 | 146 | 75 | 1010 |
| Relative humidity (%) | 21 | 82 | 80 | 78 | 77 | 79 | 81 | 79 | 80 | 82 | 82 | 83 | 83 | 80.5 |
| Total global radiation (MJ/m²) | 10 | 461.9 | 487.2 | 654.1 | 693.1 | 669.6 | 642.4 | 678.9 | 657.2 | 558 | 511.5 | 432.4 | 430.9 | 573.1 |
| Windspeed (m/s, at 2m height) | 4 | 2.1 | 2.5 | 3.4 | 3.1 | 2.8 | 2.5 | 3.6 | 3.2 | 2.6 | 2.2 | 2.5 | 2.5 | 2.8 |
| Station: | Guaro-Holguin |
| Country: | Cuba |
| WMO Code: | 99.999 |
| Altitude: | 0 |
| Latitude/Longitude | N20°41 W75°47 |
Profile description
| Ap 0-27 cm | brown (10YR 5/3, moist)clay,moderate fine subangular blocky,slightly sticky slightly plastic,no cutans,few fine pores and few pores slightly porous (<40 vol%),very frequent large irregular hard calcareous unspecified inclusions,no fragments,frequent channels,clear irregular boundary to, |
| Bi 27-75 cm | yellowish brown (10YR 5/4, moist)clay,moderate medium angular blocky and moderate medium prismatic,sticky plastic,common coarse distinct clear mottles (10YR 6/6),patchy distinct slickensides throughout cutans,few medium pores and few pores slightly porous (<40 vol%),very frequent large irregular hard manganiferous unspecified inclusions very frequent large irregular hard calcareous unspecified inclusions,no fragments,frequent channels,gradual wavy boundary to, |
| BCi 75-95 cm | brownish yellow (10YR 6/6, moist)clay,moderate coarse angular blocky and moderate coarse prismatic,sticky plastic,few coarse distinct clear mottles (10YR 5/8),continuous distinct slickensides throughout cutans,common fine pores and common pores moderately porous (40-60 vol%),few medium irregular soft calcareous nodules,no fragments,continuous weakly cemented petroferric pans,gradual irregular boundary to, |
| Ci 95-150 cm | brownish yellow (10YR 6/8, moist)clay,structureless massive,stony plastic,few distinct clear mottles (10YR 5/8),patchy moderately thick slickensides on pedfaces cutans,few common fine pores slightly porous (<40 vol%),frequent small irregular hard manganiferous concretions, |
Chemical characteristics
| Depth (cm) | C % weight/weight | Ca cmol(c)/kg | CaCO3 % weight/weight | C / N unitless | EC 1: 2.5 mS/cm | Exch. Acid cmol(c)/kg | Exch. Al cmol(c)/kg | K cmol(c)/kg | Mg cmol(c)/kg | N % | Na cmol(c)/kg | pH H2O unitless | pHKCl unitless | Sum Cations cmol(c)/kg |
| 0-27 | 1.60 | 60.9 | 7.0 | 8 | 0.29 | - | - | 1.0 | 7.5 | 0.21 | 0.6 | 8.1 | 7.2 | 70.0 |
| 27-75 | 0.32 | 56.0 | 15.0 | 8 | 0.36 | - | - | 0.4 | 11.0 | 0.04 | 4.7 | 8.7 | 7.2 | 72.1 |
| 75-95 | 0.19 | 53.9 | 18.4 | 6 | 0.72 | - | - | 0.4 | 12.8 | 0.03 | 11.2 | 9.0 | 7.3 | 78.3 |
| 95-150 | 0.06 | 47.9 | 13.0 | 2 | 1.20 | - | - | 0.4 | 12.6 | 0.03 | 19.0 | 8.8 | 7.2 | 79.9 |
| Depth (cm) | Al sat. % | Base sat. % | CEC clay cmol(c)/kg | CEC org cmol(c)/kg | CEC soil cmol(c)/kg | ECEC cmol(c)/kg | ESP % |
| 0-27 | - | 141 | 93 | 5.6 | 49.7 | - | 1 |
| 27-75 | - | 159 | 87 | 1.1 | 45.3 | - | 10 |
| 75-95 | - | 178 | 83 | 0.7 | 44.1 | - | 25 |
| 95-150 | - | 174 | 78 | 0.2 | 45.9 | - | 41 |
Physical characteristics
Particle size distribution
| Depth (cm) | Clay % weight/weight | coarse sand % weight/weight | coarse silt % weight/weight | fine sand % weight/weight | fine silt % weight/weight | Gravel % volume/volume | medium sand % weight/weight | Total sand % weight/weight | Total silt % weight/weight | very coarse sand % weight/weight | very fine sand % weight/weight |
| 0-27 | 53.0 | 5.2 | 7.0 | 5.3 | 15.9 | - | 4.6 | 24.1 | 22.9 | 5.3 | 3.7 |
| 27-75 | 60.3 | 4.4 | 3.1 | 5.1 | 16.2 | - | 4.2 | 20.3 | 19.3 | 3.6 | 3.0 |
| 75-95 | 64.8 | 1.8 | 1.7 | 3.8 | 21.9 | - | 2.4 | 11.7 | 23.6 | 1.1 | 2.6 |
| 95-150 | 67.7 | 0.1 | 3.0 | 0.5 | 27.3 | - | 0.2 | 2 | 30.3 | 0.1 | 1.1 |
Other physical data
| Depth (cm) | Bulk density kg/dm³ | Clay % weight/weight | COLE cm/cm | Spec. Surf. Area m²/g | Water disp. clay % |
| 15-20 | 1.220 | - | - | - | - |
| 0-27 | - | 53.0 | - | - | 42.2 |
| 27-75 | - | 60.3 | - | - | 41.8 |
| 25-40 | 1.340 | - | - | - | - |
| 65-70 | 1.35 | - | - | - | - |
| 75-95 | - | 64.8 | - | - | 38.4 |
| 95-150 | - | 67.7 | - | - | 37.5 |
Water retention characteristics
| Depth (cm) | Bulk density kg/dm³ | pF 0 % volume/volume | pF 1.0 % volume/volume | pF 1.5 % volume/volume | pF 2.0 % volume/volume | pF 2.3 % volume/volume | pF 2.7 % volume/volume | pF 3.4 % volume/volume | pF 4.2 % volume/volume |
| 15-20 | 1.220 | 52.1 | 51.8 | 50.7 | 49.9 | 48.5 | 47.8 | 39.0 | 31.8 |
| 25-40 | 1.340 | 50.6 | 50.4 | 48.2 | 46.8 | 45.6 | 45.0 | 42.7 | 33.2 |
| 65-70 | 1.35 | 50.6 | 50.4 | 49.2 | 48.2 | 46.8 | 46.1 | 42.9 | 33.3 |
Clay mineralogy
| Depth (cm) | Chlorite unitless | Feldspar unitless | Gibbsite unitless | Goethite unitless | Halloysite unitless | Hematite unitless | Kaolinite unitless | Mica / illite unitless | Mixed-layer unitless | Quartz unitless | Smec unitless | Vermiculite unitless |
| 0-27 | - | - | - | weak | - | - | medium to strong | - | - | weak | very strong | - |
| 27-75 | - | - | - | weak | - | - | medium to strong | - | - | weak | very strong | - |
| 75-95 | - | - | - | weak | - | - | medium to strong | - | - | weak | very strong | - |
| 95-150 | - | - | - | weak | - | - | medium to strong | - | - | weak | very strong | - |