Reference soil Peru 22: Cambisol

PE022

Cambisols occur mainly in the temperate and boreal regions of the world, where the soil’s parent material is still young or where low temperatures slow down the processes of soil formation.

Characteristics

Soils having either a cambic horizon (a horizon showing evidence of alteration with respect to the underlying material), or a mollic horizon overlying a subsoil, which has a base saturation of less than 50 percent in some part within 100 cm from the soil surface, or one of the following diagnostic horizons within the specified depth: an andic, vertic, or vitric horizon starting between 25 and 100 cm; a (petro-)plinthic or salic horizon starting between 50 and 100 cm, in absence of loamy sand or coarser textures above these horizons.

Distribution of Cambisols (rough estimation supplied by soilgrids)

Reference soil PE022: Cambisols

Short field description A very deep, well drained dark reddish brown (clay) loam. The soil profile is located in a man-made terrace on a mountain slope, near to Pomacanchi lake. The man-made terraces are in ddifferent states of degradation.

Classification

WRB 2006

WRB 1998

Haplic- Cambisol (Humic Hypereutric Chromic)

Hypereutri-Chromic- Cambisol

18-108 cm

cambic horizon

0-43 cm	ochric horizon
18-108 cm	cambic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Orthi-Chromic Cambisol

Chromic Cambisol

0-43 cm	ochric A horizon
18-108 cm	cambic B horizon
- cm	ochric A horizon

0-43 cm	ochric A horizon
18-108 cm	cambic B horizon

Local classification:	Suelo Pomacanchi

Other classification

USDA-SCS (1975)

Ustropept ustic fine-loamy mixed isomesic

Physical characteristics

Particle size distribution

Depth (cm)	Gravel % v/v	very coarse sand % w/w	coarse sand % w/w	medium sand % w/w	fine sand % w/w	very fine sand % w/w	Total sand % w/w	coarse silt % w/w	fine silt % w/w	Total silt % w/w	Clay % w/w
0-18	-	2.5	4.3	5.5	12.4	11.7	36.4	13.8	23.7	37.5	26.2
18-43	-	2.9	4.5	6.0	14.1	10.9	38.4	13.7	21.6	35.3	26.4
43-70	-	2.7	4.4	5.1	11.6	11.3	35.1	14.9	18.3	33.2	31.7
70-108	-	2.6	3.9	5.0	10.1	9.4	31.0	13.3	20.0	33.3	35.6
108-150	-	2.4	4.2	5.9	10.9	8.6	32.0	13.4	21.7	35.1	33.0

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-18	1.160	-	-	13.5	26.2
18-43	1.260	-	-	11.4	26.4
43-70	1.480	-	-	15.0	31.7
70-108	1.650	-	-	19.3	35.6
108-150	1.710	-	-	20.3	33.0

Other physical data

Depth (cm)	Bulk density kg/dm³	pF 0 % v/v	pF 1.0 % v/v	pF 1.5 % v/v	pF 2.0 % v/v	pF 2.3 % v/v	pF 2.7 % v/v	pF 3.4 % v/v	pF 4.2 % v/v
0-18	1.160	44.5	34.5	30.2	26.2	24.5	22.7	16.9	13.0
18-43	1.260	44.1	37.0	33.1	28.9	26.9	24.9	18.1	14.0
43-70	1.480	41.9	35.7	31.8	28.3	26.6	24.9	23.2	18.1
70-108	1.650	37.7	36.4	33.8	30.5	28.9	27.1	27.0	21.9
108-150	1.710	36.8	36.5	33.6	30.3	28.5	27.1	25.9	20.6

Chemical data

Depth (cm)	pH H2O	pHKCl	EC 1: 2.5 dS/m	CaCO3 % w/w	C % w/w	N %	C / N	Exch. Acid cmol(c)/kg	Exch. Al cmol(c)/kg	Ca cmol(c)/kg	Mg cmol(c)/kg	K cmol(c)/kg	Na cmol(c)/kg	Sum Cations cmol(c)/kg
0-18	6.2	5.4	0.08	-	1.65	0.18	9	-	-	11.5	2.7	0.3	0.0	14.5
18-43	6.1	5.2	0.08	-	1.94	0.19	10	-	-	10.5	2.4	0.5	0.1	13.5
43-70	6.5	5.5	0.07	0.8	1.20	0.13	9	-	-	11.9	2.4	0.2	0.0	14.5
70-108	7.0	5.9	0.1	1.4	0.86	0.10	9	-	-	16.0	2.4	0.3	0.1	18.8
108-150	8.3	7.3	0.13	3.2	0.27	0.05	5	-	-	32.9	1.7	0.3	0.1	35

Depth (cm)	Base sat. %	CEC soil cmol(c)/kg	CEC clay cmol(c)/kg	CEC org cmol(c)/kg	ECEC cmol(c)/kg	Al sat. %	ESP %
0-18	109	13.3	51	5.8	-	-	0
18-43	98	13.8	52	6.8	-	-	1
43-70	107	13.6	43	4.2	-	-	0
70-108	113	16.7	47	3.0	-	-	1
108-150	241	14.5	44	0.9	-	-	1

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-18	-	-	-	-	-	-	weak	weak to medium	-	weak	weak	weak
18-43	-	-	-	-	-	-	weak	weak to medium	-	weak	weak	weak
43-70	-	-	-	-	-	-	weak	weak to medium	-	weak	weak	weak
70-108	-	-	-	-	-	-	weak	weak to medium	-	weak	weak	weak
108-150	very weak	-	-	-	-	-	weak	weak to medium	-	very weak	weak	weak

Profile description

Ah 0-18 cm	dark reddish brown (5YR 3/3, moist) reddish brown (5YR 4/4, dry)sandy loam slightly gravelly,moderate very fine subangular blocky,slightly hard,gradual smooth boundary to,
18-43 cm	dark reddish brown (5YR 3/4, moist) brown (7.5YR 5/4, dry)loam slightly gravelly,moderate very fine subangular blocky,hard,few worm channels,gradual smooth boundary to,
BA 43-70 cm	dark reddish brown (5YR 3/3, moist) brown (7.5YR 5/4, dry)clay loam gravelly,moderate fine subangular blocky,very hard,few worm channels,diffuse smooth boundary to,
B 70-108 cm	dark reddish brown (5YR 3/4, moist)clay loam slightly stony,moderate fine subangular blocky,very firm,diffuse smooth boundary to,
C 108-150 cm	dark reddish brown (5YR 3/4, moist)sandy clay loam slightly stony,strongly coherent massive,very firm,

Kind 1 (parent material) ; Parker (eds), 1984	arkosic sandstone
Mode of accumulation or deposition of parent material	residual material
Soil Depth	160cm
Texture of parent material	loamy
Weathering Resistance	moderate
General characterization of the status of weathering of solid rock	highly

Occurrence of soil aggradation (McDonald et al., 1984)	absent
Intensity of the soil erosion type	slight
Soil erosion type	sheet
Slope stability	stable

Land improvements ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	terracing
Main type of irrigation; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	no irrigation
Land use or vegetation in the immediate vicinity of the site	semi-natural grassland, grazed
Status of vegetation; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	secondary
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	tall grassland

Altitude	3750m
Physiographic Unit	terraced land
Physiographic position of the site	middle slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	mountain
Slope	40%
Form of the slope surrounding the site	complex
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	mountainous

Drainage class ; FAO (2006) - Guidelines for soil description	well
Dry From - To	0-70cm
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	70-160cm
Estimated permeability (class) of least permeable part of the profile	moderate
Estimated run off (class)	rapid

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Average size of stone	25
Surface cracking	no cracks observed
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	no surface slaking/crusting observed
Microrelief Height: variation in height	120
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	artificial terracing/mounds
Microrelief pattern	linear
Rock outcrop class (FAO (2006) - Guidelines for soil description)	fairly rocky
Evidence of salt; Soil Survey Manual USDA, 1951	non-saline
Shape of stones (on average)	angular irregular
Surface stoniness class (FAO (2006) - Guidelines for soil description)	very few stones

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Reference soil Peru 22: Cambisol

Characteristics

Reference soil PE022: Cambisols

Classification