Reference soil Uruguay 10: Alisol

UY010

Alisols occur in the tropics and subtropics, and in the warm temperate regions of the world in relatively young landscapes. The high level of exchangeable aluminium in these soils is caused by rapid weathering of secondary high-activity clays such as vermiculite and smectite.

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 24 cmolc per kg clay or more, and which starts either 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 "alic" properties (high content of exchangeable aluminium) in the major part between 25 and 100 cm from the soil surface; moreover, only such diagnostic horizons as an ochric, albic, andic, ferric, nitic, plinthic, or vertic horizon are present.

Distribution of Alisols (rough estimation supplied by soilgrids)

Reference soil UY010: Alisols

B3 Colour of inclusions 10YR4/2 C Colour of inclusions 10YR4/3 VEGETATION: Axonopus, Eragrostis, Setaria, Piptochaetium, Malezas enans, Baccaris trimera (abundant), Eryngium.

Classification

WRB 2006

WRB 1998

Umbric-Endoleptic-Cutanic- Alisol (Humic)

Cutani-Endoleptic- Luvisol (Epidystric)

0-33 cm	umbric horizon
22-43 cm	argic horizon
-	continuous rock

0-33 cm	umbric horizon
22-43 cm	argic horizon
-	continuous hard rock

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Umbri-Humic Alisol lithic

Humic Acrisol lithic

0-33 cm	umbric A horizon
22-43 cm	argic B horizon
-	continuous hard rock

0-33 cm

umbric A horizon

Local classification:	Brunosol subéutrico típico Fr

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
0-22	-	0.2	0.3	1.3	14.4	30.4	46.6	15.5	15.1	30.6	22.9
22-33	-	0.3	0.4	1.2	12.4	28.8	43.1	13.7	15.9	29.6	27.4
33-43	-	0.2	0.4	0.5	4.0	14.8	19.9	14.9	24.7	39.6	40.6
43-69	-	0.2	0.4	0.4	4.1	16.3	21.4	10.2	32.2	42.4	36.2
69-	-	0.0	0.2	0.3	3.1	25.3	28.9	18.9	31.7	50.6	20.6

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-22	-	-	-	-	22.9
22-33	-	-	-	-	27.4
33-43	-	-	-	-	40.6
43-69	-	-	-	-	36.2
69-	-	-	-	-	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
0-22	4.3	3.9	0.5	-	2.04	0.17	12	-	-	2.6	1.9	0.4	0.0	4.9
22-33	5.2	4.2	0.14	-	1.28	0.11	12	-	-	3.3	2.3	0.2	0.2	6.0
33-43	6.1	4.3	0.09	-	0.74	0.08	9	-	-	7.1	5.7	0.3	0.5	13.6
43-69	6.7	4.7	0.09	1.5	0.30	0.04	8	-	-	8.6	6.6	0.4	0.7	16.3
69-	7.5	5.4	0.08	2.3	0.04	0	-	-	-	8.0	5.4	0.3	0.7	14.4

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 %
0-22	31	15.6	68	7.1	-	-	0
22-33	34	17.7	65	4.5	-	-	1
33-43	49	27.7	68	2.6	-	-	2
43-69	61	26.6	73	1.1	-	-	3
69-	61	23.7	115	0.1	-	-	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
0-22	-	-	-	0.10	0.00	0.70	0.10	-	-	-	0.40
22-33	-	-	-	0.10	0.00	0.90	0.20	-	-	-	0.30
33-43	-	-	-	0.20	0.00	1.40	0.30	-	-	-	0.10
43-69	-	-	-	0.10	0.00	1.30	0.20	-	-	-	0.10
69-	-	-	-	0.00	0.00	1.00	0.00	-	-	-	0.00

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-22	-	very weak	-	-	-	-	weak to medium	weak	-	medium to strong	weak	-
33-43	-	very weak	-	-	-	-	weak to medium	weak	-	weak	weak	very weak
69-	-	weak	-	-	-	-	very weak to weak	weak	-	weak	medium to strong	weak

Profile description

Ah 0-22 cm	(10YR 3/2.5, dry)sandy clay loam,firm,common medium prominent diffuse mottles (7.5YR 5/6),few pores,gradual boundary to,
Bw 22-33 cm	dark brown (10YR 3/3, dry)sandy clay,moderate coarse angular blocky,firm,common pores,medium dendritic pedodes,clear boundary to,
C 43-70 cm	yellowish red (5YR 4/6, dry)structureless,few pedodes,

Kind 1 (parent material) ; Parker (eds), 1984	sediment, unconsolidated
Remarks on Parent Materials	sediment on Yaguarí Formation
Texture of parent material	loamy

Land use or vegetation in the immediate vicinity of the site	(semi-)natural vegetation
Remarks on Land Use / Vegetation	VEGETATION: Axonopus, Eragrostis, Setaria, Piptochaetium, Malezas enanas, Baccharis trimera, Eryngium LANDUSE:
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	medium tall grassland

Altitude	100m
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.	hill
Slope	5%
Slope Aspect	north
Form of the slope surrounding the site	convex
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	rolling

Drainage class ; FAO (2006) - Guidelines for soil description	imperfect
Estimated permeability (class) of least permeable part of the profile	moderate
Drainage class - intergrade; FAO (2006) - Guidelines for soil description	moderately well

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Surface cracking	no cracks observed
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 Uruguay 10: Alisol

Characteristics

Reference soil UY010: Alisols

Classification