Reference soil Peru 10: Acrisol

PE010

Acrisols occur dominantly in the wetter parts of the tropics and subtropics and the warm temperate regions in relatively young landscapes.

Characteristics

Soils having an argic horizon (a subsurface horizon with distinct higher clay content than the overlying horizon), which has a cation exchange capacity of less than 24 cmolc per kg in some part, either starting within 100 cm from the soil surface, or within 200 cm from the soil surface if the argic horizon is overlain by loamy sand or coarser textures throughout. They have a base saturation (total amount of Ca, Mg, K and Na with respect to the cation exchange capacity) of less than 50 percent in the major part between 25 and 100 cm from the soil surface

Distribution of Acrisols (rough estimation supplied by soilgrids)

Reference soil PE010: Acrisols

Short field description A very deep, well drained, yellowish red and red clay. The soil is well structured and highly porous because of bio-activity. A thin leaf litter layer of aout 2 cm is present. The distinction between the soil horizons Bt1 to Bt4 are due to minor colour differences with gradual to diffuse boundaries. The soil site is located in 'Tierra Firme' i.e. terrain which is not flooded.

Classification

WRB 2006

WRB 1998

Haplic- Acrisol (Alumic Profondic Clayic)

Alumi-Profondic- Acrisol (Chromic)

38-150 cm

argic horizon

0-25 cm	ochric horizon
38-150 cm	argic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Alumi-Haplic Acrisol

Ferralic Cambisol

0-25 cm	ochric A horizon
38-150 cm	argic B horizon
- cm	ochric A horizon

0-25 cm	ochric A horizon
25-150 cm	cambic B horizon
-	ferralic

Local classification:	Suelo Carretera

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
0-10	-	0.1	0.2	3.6	14.8	14.4	33.1	10.5	26.6	37.1	29.9
10-25	-	0.0	0.1	2.1	10.0	11.5	23.7	16.4	24.7	41.1	35.0
25-38	-	0.1	0.1	2.1	9.5	11.3	23.1	16.9	26.2	43.1	34.0
38-65	-	0.0	0.1	2.0	9.1	11.0	22.2	15.0	21.2	36.2	41.6
65-107	-	0.0	0.1	2.1	9.1	10.2	21.5	16.9	19.4	36.3	42.1
107-150	-	0.0	0.1	1.9	7.8	9.1	18.9	11.8	18.2	30.0	51.0

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-10	1.430	-	-	6.8	29.9
10-25	1.290	-	-	16.1	35.0
25-38	1.290	-	-	18.1	34.0
38-65	1.310	-	-	14.7	41.6
65-107	1.280	-	-	11.2	42.1
107-150	1.230	-	-	6.2	51.0

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
0-10	1.430	41.1	38.9	36.8	34.2	32.1	30.9	21.8	19.9
10-25	1.290	47.8	47.3	38.1	33.6	31.2	30.1	23.3	21.4
25-38	1.290	46.2	44.6	39.5	34.9	32.6	31.5	24.5	23.3
38-65	1.310	43.5	43.5	41.1	35.9	33.1	31.6	26.7	25.3
65-107	1.280	43.2	43.2	39.0	34.4	32.2	30.9	25.0	24.0
107-150	1.230	47.0	45.6	37.8	31.8	29.4	28.2	26.3	25.1

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
0-10	4.4	3.8	0.09	-	1.76	0.03	59	4.3	2.9	0.6	0.7	0.4	0.0	1.7
10-25	4.5	3.9	0.04	-	0.70	0.10	7	5.4	3.9	0.0	0.3	0.3	0.0	0.6
25-38	4.6	3.9	0.03	-	0.50	0.08	6	5.6	4.1	0.0	0.3	0.2	0.0	0.5
38-65	4.6	3.9	0.02	-	0.39	0.07	6	5.7	4.1	0.0	0.3	0.3	0.0	0.6
65-107	4.6	3.9	0.02	-	0.33	0.06	6	6.1	4.3	0.0	0.3	0.2	0.0	0.5
107-150	4.6	3.9	0.02	-	0.27	0.06	5	6.8	5.3	0.0	0.3	0.2	0.1	0.6

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 %
0-10	8	22.0	74	6.2	-	13	0
10-25	12	5.1	15	2.5	-	76	0
25-38	8	6.4	19	1.8	-	64	0
38-65	7	8.3	20	1.4	-	49	0
65-107	6	8.3	20	1.2	-	52	0
107-150	10	6.3	12	0.9	-	84	2

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-10	-	-	-	weak	-	-	very strong	weak to medium	weak	-	weak	-
10-25	-	-	-	weak	-	-	very strong	weak to medium	weak	-	weak	-
25-38	-	-	-	weak	-	-	very strong	weak to medium	weak	-	weak	-
38-65	-	-	-	weak	-	-	very strong	weak to medium	weak	-	weak	-
65-107	-	-	-	weak	-	-	very strong	weak to medium	weak	-	weak	-
107-150	-	-	-	weak	-	-	very strong	weak	medium to strong	-	weak	-

Profile description

Ah 0-10 cm	strong brown (7.5YR 5/6, moist)clay loam,moderate medium subangular blocky,friable,frequent mycelium,gradual smooth boundary to,
10-25 cm	yellowish red (5YR 5/6, moist)clay loam,weak fine granular and weak medium subangular blocky,very friable,few pedotubules,gradual smooth boundary to,
Bt1 25-38 cm	yellowish red (5YR 5/6, moist)clay loam,weak medium subangular blocky and weak medium granular,very friable,few pedotubules,diffuse smooth boundary to,
Bt2 38-65 cm	red (2.5YR 4/6, moist)clay,weak medium subangular blocky,friable,clear smooth boundary to,
Bt3 65-107 cm	reddish yellow (5YR 6/6, moist)clay,weak medium subangular blocky,very friable,clear smooth boundary to,
Bt4 107-150 cm	reddish yellow (5YR 6/6, moist)clay,moderate medium subangular blocky parting to moderately coherent massive,firm,

Kind 1 (parent material) ; Parker (eds), 1984	non-calcareous claystone
Mode of accumulation or deposition of parent material	residual material
Remarks on Parent Materials	'Arcillolitas'
Soil Depth	107cm
Texture of parent material	clayey
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 use or vegetation in the immediate vicinity of the site	(semi-)natural vegetation
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)	evergreen woodland

Altitude	260m
Physiographic Unit	old undulating surface
Physiographic position of the site	slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	alluvial plain
Slope	5%
Form of the slope surrounding the site	undulating
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	undulating

Drainage class ; FAO (2006) - Guidelines for soil description	well
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	0-150cm
Estimated permeability (class) of least permeable part of the profile	moderate
Estimated run off (class)	medium

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Surface cracking	no cracks observed
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	no surface slaking/crusting observed
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	level
Rock outcrop class (FAO (2006) - Guidelines for soil description)	none
Evidence of salt; Soil Survey Manual USDA, 1951	non-saline
Surface stoniness class (FAO (2006) - Guidelines for soil description)	none

You are here

Reference soil Peru 10: Acrisol

Characteristics

Reference soil PE010: Acrisols

Classification