Reference soil Ecuador 12: Durisol

EC012

Durisols are found in the drier climates of the world where a source of silica is present, notably Southern Africa and Australia. Smaller occurrences are reported from the USA and the Mediterranean region.

Characteristics

Soils having a (petro-)duric horizon (horizon with accumulation of secondary silica) within 100 cm from the soil surface.

Distribution of Durisols (rough estimation supplied by soilgrids)

Reference soil EC012: Durisols

Effective soil depth is controlled by the Cangahua layer starting at 15 cm depth. Most crops cannot sufficiently penetrate the Cangahua layer. The Eucalyptus roots are able to penetrate Cangahua layer through cracks up to a depth of about 130 cm.

Classification

WRB 2006

WRB 1998

Fractipetric- Durisol

Epipetric- Durisol

15-50 cm

petroduric horizon

0-15 cm	ochric horizon
15-50 cm	petroduric horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Duri-Eutric Regosol

Eutric Regosol duripan

0-15 cm

ochric A horizon

0-15 cm

ochric A horizon

Local classification:	Cangahua

Other classification

USDA-SCS (1975)

Durandept ustic coarse-loamy over clayey 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
0-15	0	1.8	8.1	15.1	16.9	8.7	50.6	12.8	21.9	34.7	14.7
15-50	0	1.4	4.4	9.3	14.1	9.8	39.0	15.5	24.7	40.2	20.9
50-133	10	2.2	7.0	12.4	15.9	9.1	46.6	12.9	24.4	37.3	16.1
133-150	0	3.1	6.5	8.8	10.8	6.0	35.2	16.3	26.2	42.5	22.3

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
20-60	1.190	-	-	-	-
0-15	-	-	-	9.7	14.7
15-50	-	-	-	14.3	20.9
65-110	1.300	-	-	-	-
50-133	-	-	-	16.6	16.1
120-150	1.190	-	-	-	-
133-150	-	-	-	10.4	22.3

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
20-60	1.190	53.6	53.4	50.3	46.7	45.0	42.3	29.6	26.5
65-110	1.300	47.2	47.0	41.6	35.8	33.7	30.6	34.0	31.4
120-150	1.190	57.0	56.3	53.4	49.4	47.7	45.2	41.0	37.0

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
0-15	6.4	4.3	0.03	-	0.43	0.02	22	0.1	0	4.8	2.8	1.1	0.0	8.7
15-50	6.7	4.6	0.03	1.6	0.32	0.02	16	0	0	7.1	4.0	0.6	0.2	11.9
50-133	6.9	4.8	0.03	1.7	0.12	0.01	12	0	0	6.7	4.2	0.8	0.3	12.0
133-150	6.8	4.4	0.03	1.6	0.12	0.01	12	0.1	0	6.2	4.1	1.3	0.3	11.9

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 %
0-15	85	10.2	69	1.4	-	0	0
15-50	97	12.3	59	1.1	-	0	2
50-133	103	11.7	73	0.4	-	0	3
133-150	94	12.6	57	0.4	-	0	2

Depth (cm)	pH NaF	P Retention %	ODOE	Al o % w/w	Si o % w/w	Fe d % w/w	Al d % w/w	Fe p % w/w	Al p % w/w	C p % w/w	Fe o % w/w
0-15	-	12	-	0.10	0.10	1.00	0.10	0.00	0.10	-	0.10
15-50	-	15	-	0.10	0.10	1.30	0.10	0.00	0.10	-	0.20
50-133	-	9	-	0.10	0.10	1.00	0.10	0.00	0.00	-	0.10
133-150	-	13	-	0.10	0.10	1.40	0.10	0.00	0.00	-	0.10

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-15	-	-	weak	-	medium to strong	-	-	-	-	-	-	-
15-50	-	-	weak	-	medium to strong	-	-	-	-	-	-	-
50-133	-	-	weak	-	medium to strong	-	-	-	-	-	-	-
133-150	-	-	weak	-	medium to strong	-	-	-	-	-	-	-

Profile description

Ah 0-15 cm	yellowish brown (10YR 5/6, dry) dark yellowish brown (10YR 4/4, moist)very fine sandy loam,weak fine granular,soft friable non sticky non plastic,common very fine fine tubular pores,clear smooth boundary to,
Cqm1 15-50 cm	dark yellowish brown (10YR 3/4, dry) dark brown (10YR 3/3, moist)clay loam slightly gravelly,strongly coherent porous massive,very hard MI sticky plastic,many micro pores,broken massive indurated duripan pans,abrupt wavy boundary to,
Cqm2 50-133 cm	yellowish brown (10YR 5/4, dry) dark yellowish brown (10YR 4/4, moist)very fine sandy loam slightly gravelly,moderately coherent porous massive,hard firm non sticky non plastic,few micro pores and common interstitial pores,discontinuous massive weakly cemented duripan pans,gradual wavy boundary to,
C 133-150 cm	yellowish brown (10YR 5/8, dry) dark yellowish brown (10YR 4/6, moist)silty clay loam,weakly coherent porous massive,slightly hard friable slightly sticky slightly plastic,many few very fine fine to coarse pores,

Kind 1 (parent material) ; Parker (eds), 1984	acidic tuff
Mode of accumulation or deposition of parent material	ejecta ash
Remarks on Parent Materials	Cangahua tuff
Soil Depth	133cm
Texture of parent material	loamy
Weathering Resistance	poor
General characterization of the status of weathering of solid rock	slightly

Intensity of the soil erosion type	moderate
Intensity of the soil erosion type (second entry)	slight
Soil erosion type	sheet
Soil erosion type (second entry)	rill

Land use or vegetation in the immediate vicinity of the site	afforestation
Remarks on Land Use / Vegetation	VEGETATION: Eucalyptus globulus and Kikuyu grass LANDUSE:

Altitude	2400m
Physiographic Unit	hill
Physiographic position of the site	lower slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	hill
Slope	35%
Slope Aspect	south-west
Form of the slope surrounding the site	convex
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	hilly

Lower limit of a slow permeable or stagnating layer in the profile	50cm
Drainage class ; FAO (2006) - Guidelines for soil description	well
Dry From - To	10-150cm
Flooding frequency (FAO, 1986)	never
Depth to groundwater table	600cm
Kind of ground water table (USDA, 1979)	groundwater table observed
Moist From - To	0-10cm
Estimated permeability (class) of least permeable part of the profile	slow
Estimated run off (class)	rapid
Upper limit of a slow permeable or stagnating layer in the profile	15cm

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	surface slaked; sorted sand/silt, some clay films
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 Ecuador 12: Durisol

Characteristics

Reference soil EC012: Durisols

Classification