Soil type characteristics:
Ferralsols occur in tropical and subtropical regions of the world, mainly on old and stable land surfaces.
Characteristics
Soils having a ferralic horizon (strongly weathered horizon with low-activity clays and very low amounts of weatherable minerals) between 25 and 200 cm from the soil surface. They lack a nitic horizon (a horizon with strongly developed, nut-shaped structure) and do not have a layer which fulfils the requirements of an argic horizon and which has, in the upper 30 cm, 10 percent or more water-dispersible clay.
Distribution of Ferralsols (rough estimation supplied by soilgrids)
Description:
Reference soil KE011: Ferralsols
Ferralsol
General information:
| Location | Kilifi District, Arabuko Sokoko Forest, 5km NW of Roka along Rok-Dida road |
| Date | 1900-01-01 |
| Lat/Lon | -3.4500, 39.8333 |
Code:
KE011
Parent material
| Mode of accumulation or deposition of parent material | marine sediments |
| Kind 1 (parent material) ; Parker (eds), 1984 | sandstone |
| Remarks on Parent Materials | Margarini sands |
| Texture of parent material | loamy |
Physiography
| Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006) | flat or almost flat |
| Physiographic Unit | marine terrace |
| Altitude | 160m |
| Slope | 1% |
| Form of the slope surrounding the site | straight |
| Physiographic position of the site | flat |
| Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne. | coastal plain |
Hydrology and drainage
| (Estimated) minimum (upper) depth to groundwater table | 0cm |
| Flooding frequency (FAO, 1986) | never |
| Depth to groundwater table | 0cm |
| Kind of ground water table (USDA, 1979) | no groundwater table observed |
| Drainage class ; FAO (2006) - Guidelines for soil description | well |
| Estimated permeability (class) of least permeable part of the profile | moderate |
| Estimated run off (class) | slow |
Land use
| Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006) | evergreen woodland |
| Land use or vegetation in the immediate vicinity of the site | (semi-)natural vegetation |
Surface characteristics
| Microrelief Height: variation in height | 0 |
| Evidence of alkali ; Soil Survey Manual USDA, 1951 | non-alkaline |
| Rock outcrop class (FAO (2006) - Guidelines for soil description) | none |
| Surface cracking | no cracks observed |
| Evidence of salt; Soil Survey Manual USDA, 1951 | non-saline |
| Surface stoniness class (FAO (2006) - Guidelines for soil description) | none |
Classification
WRB 2006
| Lixic-Vetic Ferralsol (Eutric Rhodic) |
| 11-250 cm | ferralic horizon |
WRB 1998
| Veti-Lixic Ferralsol (Hypereutric Rhodic) |
FAO-UNESCO-ISRIC 1988
| Lixi-Rhodic Ferralsol |
| 0-11 cm | ochric A horizon |
| 11-250 cm | ferralic B horizon |
| 12-250 cm | argic B horizon |
FAO-UNESCO-ISRIC 1974
| Rhodic Ferralsol |
| 0-11 cm | ochric A horizon |
| 11-250 cm | oxic B horizon |
Other classification
| USDA-NRCS (1999) | Rhodic Kandiustalf |
| USDA-SCS (1975) | Rhodic Haplustox ustic loamy kaolinitic isohyperthermic |
Other
| Description of a site | Ferralsol |
Profile description
| Ah 0-11 cm | (10YR 2.5/ 2, moist), dusky red (10R 3/4, dry)sandy clay loam,very weak fine and medium subangular blocky to granular,soft very friable sticky slightly plastic,many fine pores,many fine and medium roots,non calcareous,clear smooth boundary to, |
| AB 11-22 cm | (10YR 2.5/2, moist), dusky red (10R 3/4, dry)sandy clay loam,very weak fine and medium subangular blocky to granular,slightly hard very friable slightly sticky slightly plastic,many very fine and fine pores,common fine and medium roots,non calcareous,diffuse smooth boundary to, |
| Bo1 22-50 cm | dusky red (10R 3/3, moist)sandy clay loam,very weak fine and medium subangular blocky to granular,soft very friable slightly sticky slightly plastic,many very fine and fine pores,few fine and medium roots,non calcareous,diffuse smooth boundary to, |
| Bo2 50-85 cm | dusky red (10R 3/3, moist)sandy clay loam,very weak medium and coarse subangular blocky to granular,soft very friable slightly sticky slightly plastic,many very fine and fine pores,few fine and medium roots,non calcareous,diffuse smooth boundary to, |
| Bo3 85-180 cm | dusky red (10R 3/3, moist)sandy clay loam,very weak medium subangular blocky to granular,soft very friable slightly sticky slightly plastic,many very fine and fine pores,few fine and medium roots,non calcareous, |
Chemical characteristics
| Depth (cm) | Na cmol(c)/kg | Sum Cations cmol(c)/kg | Ca cmol(c)/kg | EC 1: 2.5 mS/cm | pHKCl unitless | K cmol(c)/kg | Mg cmol(c)/kg | pH H2O unitless | Exch. Acid cmol(c)/kg | C / N unitless | Exch. Al cmol(c)/kg | N % | C % weight/weight | CaCO3 % weight/weight |
| 0-11 | 0.5 | 1.7 | 0.4 | 0.05 | 4.3 | 0.2 | 0.6 | 5.3 | 0.2 | 13 | 0.2 | 0.07 | 0.90 | - |
| 11-22 | 0.2 | 1 | 0.4 | 0.03 | 4.2 | 0.1 | 0.3 | 5.1 | 0.3 | 12 | 0.2 | 0.04 | 0.48 | - |
| 22-50 | 0.0 | 1 | 0.0 | 0.03 | 4.5 | 0.0 | 1.0 | 5.3 | 0.1 | 12 | 0.0 | 0.02 | 0.24 | - |
| 50-85 | 0.4 | 1.7 | 0.0 | 0.03 | 4.5 | 0.1 | 1.2 | 5.3 | 0.1 | - | 0.0 | - | 0.15 | - |
| 85-180 | 0.5 | 2.1 | 0.0 | 0.03 | 4.5 | 0.1 | 1.5 | 5.3 | 0.1 | - | 0.0 | - | 0.12 | - |
| 180-250 | 0.1 | 2.1 | 0.4 | 0.03 | 4.3 | 0.1 | 1.5 | 5.1 | 0.1 | - | 0.1 | - | 0.11 | - |
| Depth (cm) | Base sat. % | Al sat. % | CEC soil cmol(c)/kg | ECEC cmol(c)/kg | CEC clay cmol(c)/kg | CEC org cmol(c)/kg | ESP % |
| 0-11 | 81 | 10 | 2.1 | - | 14 | 3.2 | 24 |
| 11-22 | 63 | 13 | 1.6 | - | 8 | 1.7 | 13 |
| 22-50 | 63 | 0 | 1.6 | - | 3.0 | 0.8 | 0 |
| 50-85 | 142 | 0 | 1.2 | - | 4 | 0.5 | 33 |
| 85-180 | 131 | 0 | 1.6 | - | 4 | 0.4 | 31 |
| 180-250 | 124 | 6 | 1.7 | - | 4 | 0.4 | 6 |
| Depth (cm) | pH NaF unitless | Fe o % weight/weight | Al p % weight/weight | Al o % weight/weight | ODOE unitless | C p % weight/weight | P Retention % | Fe p % weight/weight | Si o % weight/weight | Fe d % weight/weight | Al d % weight/weight |
| 0-11 | - | 0.04 | 0.04 | 0.04 | - | - | - | 0.03 | - | 1.35 | 0.07 |
| 11-22 | - | 0.05 | 0.03 | 0.04 | - | - | - | 0.02 | - | 1.79 | 0.08 |
| 22-50 | - | 0.07 | 0.01 | 0.05 | - | - | - | 0.00 | - | 2.32 | 0.10 |
| 50-85 | - | 0.07 | 0.01 | 0.06 | - | - | - | 0.00 | - | 2.77 | 0.10 |
| 85-180 | - | 0.08 | 0.00 | 0.05 | - | - | - | 0.00 | - | 3.41 | 0.12 |
| 180-250 | - | 0.06 | 0.01 | 0.05 | - | - | - | 0.00 | - | 3.29 | 0.12 |
| Depth (cm) | P Bray mg/kg | P Olsen mg/kg | pH CaCl2 unitless | CaSO4.2H2O % |
| 0-11 | 4.3 | - | - | - |
| 11-22 | 2.5 | - | - | - |
| 22-50 | 1.1 | - | - | - |
| 50-85 | 0.6 | - | - | - |
| 85-180 | 0.6 | - | - | - |
| 180-250 | 0.7 | - | - | - |
Physical characteristics
Particle size distribution
| Depth (cm) | medium sand % weight/weight | fine silt % weight/weight | fine sand % weight/weight | Clay % weight/weight | Total sand % weight/weight | coarse sand % weight/weight | very coarse sand % weight/weight | Gravel % volume/volume | Total silt % weight/weight | coarse silt % weight/weight | very fine sand % weight/weight |
| 0-11 | 49.8 | 0.2 | 29.4 | 15.1 | 83.5 | 3.1 | 0.1 | - | 1.3 | 1.1 | 1.1 |
| 11-22 | 44.2 | 0.6 | 32.7 | 19.2 | 80 | 1.9 | 0.1 | - | 0.8 | 0.2 | 1.1 |
| 22-50 | 39.4 | 0.6 | 31.1 | 25.9 | 73.3 | 1.6 | 0.0 | - | 0.8 | 0.2 | 1.2 |
| 50-85 | 37.0 | 1.1 | 26.1 | 32.2 | 66.1 | 1.6 | 0.0 | - | 1.8 | 0.7 | 1.4 |
| 85-180 | 34.2 | 0.4 | 24.7 | 36.9 | 61.8 | 1.5 | 0.0 | - | 1.3 | 0.9 | 1.4 |
| 180-250 | 30.0 | 1.5 | 25.9 | 38.9 | 58.7 | 1.1 | 0.0 | - | 2.4 | 0.9 | 1.7 |
Other physical data
| Depth (cm) | Water disp. clay % | Clay % weight/weight | Bulk density kg/dm³ | COLE cm/cm | Spec. Surf. Area m²/g |
| 12-17 | - | - | 1.52 | - | - |
| 0-11 | 3.0 | 15.1 | - | - | 19 |
| 11-22 | 3.5 | 19.2 | - | - | 22 |
| 48-53 | - | - | 1.43 | - | - |
| 98-103 | - | - | 1.42 | - | - |
| 22-50 | 0.5 | 25.9 | - | - | - |
| 50-85 | 0.5 | 32.2 | - | - | 34 |
| 85-180 | 2.5 | 36.9 | - | - | 43 |
| 180-250 | 2.0 | 38.9 | - | - | - |
Water retention characteristics
| Depth (cm) | pF 4.2 % volume/volume | pF 2.7 % volume/volume | pF 2.0 % volume/volume | pF 1.0 % volume/volume | pF 1.5 % volume/volume | pF 3.4 % volume/volume | Bulk density kg/dm³ | pF 2.3 % volume/volume | pF 0 % volume/volume |
| 12-17 | 9.0 | 13.1 | 16.2 | 38.8 | 29.5 | 9.3 | 1.52 | 14.4 | 40.0 |
| 48-53 | 10.4 | 14.6 | 20.8 | 42.0 | 32.8 | 11.3 | 1.43 | 17.1 | 43.3 |
| 98-103 | 13.5 | 17.0 | 24.3 | 42.7 | 35.3 | 14.7 | 1.42 | 20.1 | 43.0 |
Elemental composition of the clay
| Depth (cm) | K2O % weight/weight | SiO2 % weight/weight | TiO2 % weight/weight | Na2O % weight/weight | CaO % weight/weight | Al2O3 % weight/weight | Fe2O3 % weight/weight | MgO % weight/weight |
| 0-11 | 0.13 | 36.4 | 0.70 | - | 0.03 | 30.5 | 11.5 | 0.30 |
| 11-22 | 0.11 | 36.0 | 0.60 | - | 0.03 | 30.4 | 11.2 | 0.10 |
| 22-50 | 0.10 | 37.7 | 0.60 | - | 0.02 | 31.7 | 11.6 | 0.20 |
| 50-85 | 0.10 | 37.7 | 0.60 | - | 0.01 | 31.9 | 11.4 | 0.10 |
| 85-180 | 0.09 | 34.8 | 0.60 | - | 0.02 | 29.7 | 10.9 | 0.10 |
| 180-250 | 0.10 | 36.8 | 0.70 | - | 0.02 | 30.9 | 11.5 | 0.20 |
| Depth (cm) | SiO2 / R mol/mol | P2O5 % weight/weight | Ign.Loss clay % weight/weight | SiO2/Al2O3 mol/mol | SiO2/Fe2O3 mol/mol | Total Clay % weight/weight | MnO2 % weight/weight | Al2O3/Fe2O3 mol/mol |
| 0-11 | 1.6 | 0.12 | 15.5 | 2 | 8.4 | 95.88 | 0.70 | 4.2 |
| 11-22 | 1.6 | 0.06 | 14.5 | 2 | 8.5 | 93.5 | 0.50 | 4.3 |
| 22-50 | 1.6 | 0.05 | 13.6 | 2 | 8.6 | 95.97 | 0.40 | 4.3 |
| 50-85 | 1.6 | 0.03 | 13.5 | 2 | 8.8 | 95.64 | 0.30 | 4.4 |
| 85-180 | 1.6 | 0.02 | 14.1 | 2 | 8.5 | 90.53 | 0.20 | 4.3 |
| 180-250 | 1.6 | 0.06 | 13.1 | 2 | 8.5 | 93.58 | 0.20 | 4.2 |
Elemental composition of the soil
| Depth (cm) | K2O % weight/weight | CaO % weight/weight | MgO % weight/weight | SiO2 % weight/weight | Al2O3 % weight/weight | Fe2O3 % weight/weight | TiO2 % weight/weight | Na2O % weight/weight |
| 0-11 | 0.25 | 0.02 | 0.02 | 83.3 | 5.8 | 3.8 | 1.29 | - |
| 11-22 | 0.25 | 0.02 | 0.02 | 83.9 | 7.5 | 4.6 | 1.45 | - |
| 22-50 | 0.27 | 0.02 | 0.03 | 78.8 | 10.6 | 5.6 | 1.41 | - |
| 50-85 | 0.26 | 0.01 | 0.02 | 74.6 | 12.7 | 6.1 | 1.34 | - |
| 85-180 | 0.26 | 0.01 | - | 70.2 | 14.3 | 7.0 | 1.48 | - |
| 180-250 | 0.26 | - | 0.06 | 72.6 | 14.3 | 7.0 | 1.45 | - |
| Depth (cm) | P2O5 % weight/weight | MnO2 % weight/weight | LOI % weight/weight | SiO2 / R mol/mol | Al2O3/Fe2O3 mol/mol | SiO2/Fe2O3 mol/mol | SiO2 / Al2O3 mol/mol |
| 0-11 | - | 0.25 | 4.2 | 17.2 | 2.4 | 58.4 | 24.4 |
| 11-22 | - | 0.28 | 3.4 | 13.6 | 2.6 | 48.6 | 19 |
| 22-50 | - | 0.26 | 4.1 | 9.4 | 3.0 | 37.5 | 12.6 |
| 50-85 | - | 0.22 | 3.9 | 7.6 | 3.3 | 32.6 | 10 |
| 85-180 | - | 0.17 | 5.5 | 6.3 | 3.2 | 26.7 | 8.3 |
| 180-250 | - | 0.10 | 5.3 | 6.6 | 3.2 | 27.6 | 8.6 |
Clay mineralogy
| Depth (cm) | Mixed-layer unitless | Gibbsite unitless | Chlorite unitless | Halloysite unitless | Kaolinite unitless | Smec unitless | Quartz unitless | Goethite unitless | Hematite unitless | Feldspar unitless | Vermiculite unitless | Mica / illite unitless |
| 0-11 | - | - | - | - | very strong | - | - | weak to medium | - | - | - | - |
| 11-22 | - | - | - | - | very strong | - | - | weak to medium | - | - | - | - |
| 22-50 | - | - | - | - | very strong | - | - | weak to medium | - | - | - | - |
| 50-85 | - | - | - | - | very strong | - | - | weak to medium | - | - | - | - |
| 85-180 | - | - | - | - | very strong | - | - | weak to medium | - | - | - | - |
| 180-250 | - | - | - | - | very strong | - | - | weak to medium | - | - | - | - |
Mineral sand
| Depth (cm) | Quartz % weight/weight | Light Fra. sand % weight/weight | Opaque % weight/weight | Plagioclase % weight/weight | Heavy Frac. sand % weight/weight | K-Feldspar % weight/weight |
| 85-180 | 96 | 94.8 | 65 | - | 5.2 | 4 |
Minerals
| Depth (cm) | Apatite % weight/weight | Andalusite % weight/weight | Hornblende (basaltic) % weight/weight | Augite % weight/weight | Biotite % weight/weight | Anatase % weight/weight |
| 85-180 | - | 1 | - | - | - | - |
| Depth (cm) | Garnet % weight/weight | Epidote % weight/weight | Disthene % weight/weight | Glaucophane % weight/weight | Chloritic % weight/weight | Brookite % weight/weight |
| 85-180 | - | - | 11 | - | - | - |
| Depth (cm) | Muscovite % weight/weight | Grossular % weight/weight | Rutile % weight/weight | Grenate % weight/weight | Spinel % weight/weight | Sillimanite % weight/weight |
| 85-180 | - | - | 23 | - | - | 55 |
