Reference soil Ecuador 10: Phaeozem

EC010

Phaeozems occur all over the world, but especially on the more moist side of the steppe regions, bordering Chernozems.

Characteristics

Soils having a mollic horizon (deep, brownish or blackish surface horizon with a significant accumulation of organic matter and high base saturation); a base saturation of 50 percent or more between 25 and 100 cm from the soil surface; a calcium carbonate-free soil matrix at least to a depth of 100 cm from the soil surface, or to a contrasting layer between 25 and 100 cm; no diagnostic horizons other than an albic, argic, cambic or vertic horizon, or a petrocalcic horizon in the substratum.

Distribution of Phaeozems (rough estimation supplied by soilgrids)

Reference soil EC010: Phaeozems

EC10 is comparable to profile Ecuador No.12 in: part III-tourguide for Ecuador of the sixth international soil classification workshop (1984). The soil has been redescribed and resampled by G.del Posso in May 1988, additionally two monoliths have been taken. The volcanic ash is probably of an acid type. To a depth of 130 cm are present a few (1%) artifacts, fragments of brick, stone and tools.

Classification

WRB 2006

WRB 1998

Endovitric- Phaeozem (Pachic)

Pachi-Vitric- Phaeozem

0-83 cm	mollic horizon
102-150 cm	argic horizon
-	vitric

0-83 cm	mollic horizon
102-150 cm	argic horizon
52-102 cm	vitric horizon
-	strongly humic

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Andi-Luvic Phaeozem

Luvic Phaeozem

0-83 cm	mollic A horizon
102-150 cm	argic B horizon
-	andic
-	strongly humic

0-83 cm	mollic A horizon
102-150 cm	argillic B horizon

Other classification

USDA-SCS (1975)

Argiudoll ustic fine-loamy mixed isohyperthermic

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	0.1	0.2	0.6	15.4	16.3	32.6	20.0	27.3	47.3	20.1
10-52	0	0.1	0.1	0.7	17.2	15.2	33.3	18.8	35.8	54.6	12.2
52-83	0	0.0	0.1	0.5	20.3	14.9	35.8	17.0	35.6	52.6	11.5
83-102	0	0.1	0.3	0.8	17.3	17.0	35.5	17.5	37.7	55.2	9.2
102-130	0	0.1	0.2	0.6	16.8	13.9	31.6	14.8	30.1	44.9	23.6
130-150	0	0.1	0.2	0.8	7.4	6.1	14.6	6.9	15.3	22.2	63.2

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	-	-	-	3.0	20.1
10-25	1.350	-	-	-	-
30-60	0.750	-	-	-	-
10-52	-	-	-	2.5	12.2
52-83	-	-	-	0.5	11.5
110-130	0.840	-	-	-	-
83-102	-	-	-	2.1	9.2
102-130	-	-	-	12.1	23.6
130-150	-	-	-	40.3	63.2

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
10-25	1.350	48.0	47.2	43.4	41.0	39.5	37.7	50.2	43.1
30-60	0.750	66.3	66.1	58.5	48.5	44.6	39.0	22.4	17.1
110-130	0.840	60.9	60.8	50.8	42.4	39.8	36.5	19.1	16.6

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
0-10	6.8	6.0	0.28	0.9	4.09	0.40	10	-	-	21.8	3.9	1.2	0.0	26.9
10-52	6.8	5.6	0.05	-	1.71	0.19	9	-	-	11.1	2.0	0.8	0.1	14.0
52-83	6.8	5.4	0.04	-	1.49	0.11	14	-	-	10.2	0.9	2.1	0.0	13.2
83-102	6.4	5.1	0.04	-	1.48	0.11	13	-	-	6.1	0.6	0.9	0.1	7.7
102-130	6.7	4.9	0.03	-	0.35	0.03	12	-	-	5.6	0.8	0.8	0.2	7.4
130-150	6.5	4.8	0.06	1.6	0.22	0.04	6	-	-	6.8	2.0	1.2	0.5	10.5

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	-	26.9	-	14.4	-	-	0
10-52	83	16.8	138	6.0	-	-	1
52-83	72	18.4	160	5.3	-	-	0
83-102	57	13.5	147	5.3	-	-	1
102-130	80	9.3	39	1.4	-	-	2
130-150	-	14.4	-	0.7	-	-	3

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
0-10	9.2	37	-	0.70	0.50	1.20	0.30	0.10	0.20	-	0.60
10-52	9.8	26	-	1.60	1.00	1.30	0.50	0.10	0.20	-	0.80
52-83	9.8	77	-	1.60	1.10	1.50	0.40	0.10	0.20	-	0.80
83-102	10.0	70	-	2.90	1.70	1.60	0.40	0.10	0.20	-	0.60
102-130	8.4	69	-	0.20	0.20	1.80	0.20	0.00	0.10	-	0.60
130-150	8.4	47	-	0.20	0.10	3.10	0.30	0.00	0.10	-	0.50

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-10	-	weak	-	-	weak	-	-	-	-	-	-	-
10-52	-	weak	-	-	weak	-	-	-	-	-	-	-
52-83	-	weak	-	-	weak	-	-	-	-	-	-	-
83-102	-	weak	-	-	weak	-	-	-	-	-	-	-
102-130	-	weak	-	-	medium to strong	-	-	-	-	-	-	-
130-150	-	weak	-	-	medium to strong	-	-	-	-	-	-	-

Profile description

Ah 0-10 cm	very dark brown (10YR 2/2, moist)loam,moderate coarse subangular blocky parting to strong medium and coarse granular,friable slightly sticky slightly plastic,many very fine medium tubular pores and many fine interstitial pores,very few pottery inclusions,clear wavy boundary to,
Bo 10-52 cm	dark brown (7.5YR 3/2, moist)loam,moderate medium subangular blocky,friable slightly sticky slightly plastic weakly smeary,many very fine medium tubular pores,very few pottery inclusions,clear wavy boundary to,
2Ab 52-83 cm	very dark brown (10YR 2/2, moist)loam,weak coarse subangular blocky,friable slightly sticky slightly plastic moderately smeary,many very fine medium tubular pores,very few pottery inclusions,gradual wavy boundary to,
3Btb1 83-102 cm	very dark greyish brown (10YR 3/2, moist)silt loam,moderate medium and coarse subangular blocky,very friable sticky slightly plastic strongly smeary,patchy thin pressure on pedfaces cutans,many very fine medium tubular pores,very few pottery inclusions,gradual wavy boundary to,
3Btb2 102-130 cm	dark brown (7.5YR 3/2, moist)clay loam,weak coarse subangular blocky,friable sticky plastic strongly smeary,continuous thin clay on pedfaces cutans,many very fine medium tubular pores,very few pottery inclusions,diffuse wavy boundary to,
4Btb3 130-150 cm	dark reddish brown (5YR 3/2, moist)clay,moderate medium and coarse prismatic parting to moderate medium and coarse angular blocky,firm sticky plastic weakly smeary,continuous thin clay on pedfaces cutans,many very fine medium tubular pores,

Depth1	52cm
Kind 1 (parent material) ; Parker (eds), 1984	pyroclastic, unconsolidated
Kind 2 (parent material) (second entry); Parker (eds), 1984	pyroclastic, unconsolidated
Mode of accumulation or deposition of parent material	ejecta ash
Mode of accumulation or deposition of parent material (second entry)	ejecta ash
Remarks on Parent Materials	multiple ash layers
Soil Depth	150cm
Texture of parent material	loamy
Texture of parent material (second entry)	clayey
Weathering Resistance	poor
Weathering Resistance (second entry)	poor
General characterization of the status of weathering of solid rock	slightly
General characterization of the status of weathering of solid rock (second entry)	partially or moderately

Major crops	cocoa
Land use or vegetation in the immediate vicinity of the site	medium level arable farming
Remarks on Land Use / Vegetation	VEGETATION: Forest with cocoa LANDUSE: Nearby maize and soybean
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	semi-deciduous forest

Altitude	120m
Physiographic Unit	higher part of fan
Physiographic position of the site	crest
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	alluvial fan
Slope	1%
Form of the slope surrounding the site	straight
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	flat or almost flat

Drainage class ; FAO (2006) - Guidelines for soil description	well
Flooding frequency (FAO, 1986)	never
Depth to groundwater table	900cm
Kind of ground water table (USDA, 1979)	groundwater table observed
Estimated permeability (class) of least permeable part of the profile	slow
Estimated run off (class)	slow
Wet From To	0-170cm

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
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

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Reference soil Ecuador 10: Phaeozem

Characteristics

Reference soil EC010: Phaeozems

Classification