Reference soil China 29: Acrisol

CN029

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 CN029: Acrisols

PROFILE DESCRIPTION : Moderately deep, well drained, strong brown clay derived from Devonian shale. The dark yellowish brown topsoil has moderately developed subangular blocky structures and has a high organiccarbon content. The subsoil is strongly angular blocky, becoming stony below 70 cm depth. Soil reaction is strongly acid throughout. PARENT MATERIAL: it is assumed that the moderately weathered stones occuring in the 2Bt horizon are the result of colluvial action, hence the two parent materials / SOIL DEPTH: soil can vary in depth over short distances. In places on more eroded sites (steeper slopes) or on more resistant facies of shale it is less than 50 cm. Pockets of strongly weathered shale occur side-by-side in the R horizon. Slide nos. of the ISRIC collection: 13917-13921 (landscape, profile, profile details, monolith taking).

Classification

WRB 2006

WRB 1998

Cutanic- Acrisol (Hyperdystric Chromic)

Chromi-Hyperdystric- Acrisol

5-90 cm

argic horizon

0-15 cm	ochric horizon
5-90 cm	argic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Alumi-Haplic Acrisol

Ferric Acrisol

0-15 cm	ochric A horizon
- cm	cambic B horizon
- cm	ochric A horizon
-	ferralic

0-15 cm	ochric A horizon
15-90 cm	argillic B horizon
-	ferralic
-	ferric

Local classification:	Haplic para-red soil; Acidi-Udic Cambosol
Common name:	Brown clay-leached soil

Other classification

USDA-SCS (1975)

Dystrochrept udic fine mixed thermic

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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	-	0.3	0.6	0.8	5.4	11.6	18.7	19.3	20.2	39.5	41.8
20-40	-	0.2	0.6	1.0	7.8	8.6	18.2	11.9	29.5	41.4	40.4
50-70	-	0.6	1.0	1.5	6.4	11.2	20.7	11.7	29.7	41.4	38.0
70-90	-	1.0	2.2	2.7	12.6	10.2	28.7	15.7	36.2	51.9	19.4
100-120	-	1.4	3.9	6.7	18.3	17.2	47.5	10.9	29.0	39.9	12.6

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-15	-	-	-	-	41.8
0-5	0.732	-	-	-	-
50-55	1.295	-	-	-	-
20-40	-	-	-	-	40.4
50-70	-	-	-	-	38.0
70-90	-	-	-	-	19.4
100-120	-	-	-	-	12.6

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
0-5	0.732	53.5	42.0	36.2	31.5	31.0	27.2	18.7	16.8
50-55	1.295	46.0	42.6	39.3	36.0	35.5	33.4	33.1	25.4

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	4.1	3.3	0.05	-	3.09	0.18	17	8.2	7.9	0.8	0.0	0.1	0.0	0.9
20-40	4.2	3.3	0.02	-	0.60	0.06	10	5.2	4.9	0.2	0.0	0.0	0.0	0.2
50-70	4.2	3.4	0.02	-	0.36	0.05	7	3.5	3.4	0.2	0.0	0.0	0.0	0.2
70-90	4.4	3.7	0.01	-	0.14	0.04	4	2.4	2.2	0.2	0.0	0.0	0.0	0.2
100-120	4.4	4.0	0.01	-	0.05	0.02	3	1.6	1.4	0.2	0.0	0.0	0.0	0.2

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	6	15.3	37	10.8	-	52	0
20-40	3	6.5	16	2.1	-	75	0
50-70	2	8.8	23	1.3	-	39	0
70-90	5	3.7	19	0.5	-	59	0
100-120	8	2.5	20	0.2	-	56	0

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	-	-	-	-	-	1.60	0.30	-	-	-	-
20-40	-	-	-	-	-	1.90	0.30	-	-	-	-
50-70	-	-	-	-	-	2.00	0.30	-	-	-	-
70-90	-	-	-	-	-	1.70	0.20	-	-	-	-
100-120	-	-	-	-	-	1.60	0.20	-	-	-	-

Depth (cm)	CaSO4.2H2O %	P Bray mg/kg	P Olsen mg/kg	pH CaCl2	clay_noncarbonate % w/w	clay_carbonate % w/w	phosphorus4 mg/kg	phosphorus1 mg/kg	total_sulfur % w/w
0-15	-	0.6	-	-	-	-	-	-	-
20-40	-	0.0	-	-	-	-	-	-	-
50-70	-	0.0	-	-	-	-	-	-	-
70-90	-	0.0	-	-	-	-	-	-	-
100-120	-	0.0	-	-	-	-	-	-	-

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-15	weak	-	-	weak	-	-	medium to strong	medium to strong	weak	-	-	very weak
20-40	weak	-	-	weak	-	-	medium to strong	medium to strong	weak	-	-	weak
50-70	weak	-	-	weak	-	-	medium to strong	medium to strong	weak	-	-	weak
70-90	weak	-	-	weak	-	-	medium to strong	medium to strong	weak	-	-	weak
100-120	weak	-	-	medium to strong	-	-	medium to strong	medium to strong	weak	-	-	weak

Profile description

Ah 0-15 cm	yellowish brown (10YR 5/6, dry) dark yellowish brown (10YR 4/6, moist)clay loam,moderate fine and medium subangular blocky,hard friable slightly sticky slightly plastic,common fine medium continuous exped vesicular random pores highly porous (>60 vol%),frequent worm channels,clear wavy boundary to,
Bt1 15-70 cm	reddish yellow (7.5YR 6/8, dry) strong brown (7.5YR 5/6, moist)clay,very strong very coarse angular blocky parting to strong medium and coarse angular blocky,very hard firm very sticky very plastic,continuous moderately thick clay and sesquioxide on pedfaces cutans,few common very fine fine continuous inped tubular random pores slightly porous (<40 vol%),few channels,clear wavy boundary to,
2Bt2 70-90 cm	reddish yellow (7.5YR 6/8, dry) strong brown (7.5YR 5/6, moist)strong brown (7.5YR 5/6, moist),clay,clay stony,very strong coarse angular blocky parting to strong MF angular blocky,very hard firm very sticky very plastic,friable sticky slightly plastic,broken moderately thick clay and sesquioxide on pedfaces cutans,few very fine fine continuous inped tubular random pores slightly porous (<40 vol%),frequent medium gravel strongly weathered rotten shale fragments,frequent medium gravel strongly weathered weathered shale fragments,no biological activity,no biological activity,clear irregular boundary to,

Depth1	70cm
Kind 1 (parent material) ; Parker (eds), 1984	shale
Kind 2 (parent material) (second entry); Parker (eds), 1984	shale
Mode of accumulation or deposition of parent material	colluvial
Mode of accumulation or deposition of parent material (second entry)	residual material
Remarks on Parent Materials	Devonian shale
Soil Depth	90cm
Texture of parent material	clayey
Texture of parent material (second entry)	clayey
Weathering Resistance	moderate
General characterization of the status of weathering of solid rock	highly
General characterization of the status of weathering of solid rock (second entry)	highly

Occurrence of soil aggradation (McDonald et al., 1984)	not apparent
Intensity of the soil erosion type	slight
Soil erosion type	gully
Slope stability	locally unstable

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 vegetation
Remarks on Land Use / Vegetation	VEGETATION: Masson pine, fir, bamboo, fern
Rotation scheme ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	crop rotation scheme not relevant
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)	semi-deciduous woodland

Altitude	600m
Physiographic Unit	higher part lower montains
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	30%
Slope Aspect	north-north-east
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	0-90cm
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	90-120cm
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
Surface cracking	small cracks (width less than 1 cm, or depth less than 50 cm)
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	no surface slaking/crusting 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 China 29: Acrisol

Characteristics

Reference soil CN029: Acrisols

Classification