Reference soil China 47: Alisol

CN047

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 CN047: Alisols

PROFILE DESCRIPTION : Deep, well drained, strong brown clay to silty clay developed from solid rock derived from shale. GENERAL LANDFORM: in between the low mountains and hills, small valleys are found, filled with colluvium, where irrigated rice is cultivated. The different geomorphological units form part of the broad Pingba basin / PARENT MATERIAL: the soil is developed on shale, outcropping in the inmediate surroundings in form of some low steep bare mountains / SOIL DEPTH: hills which are more gently sloping have a thick solumn (yellow earth) and the parent material is at relatively great depth / GENERAL SOIL INFORMATION: nearby yellowish red coloured soils on Quaternary clay (CN048) are also classified as Yellow soils in the new Chinese soil classification.

Classification

WRB 2006

WRB 1998

Cutanic- Alisol (Alumic Clayic)

Dystri-Cutanic- Luvisol

15-140 cm

argic horizon

0-15 cm	ochric horizon
15-140 cm	argic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Xanthi-Haplic Alisol

Orthic Acrisol

0-15 cm	ochric A horizon
15-140 cm	argic B horizon
- cm	argic B horizon
- cm	ochric A horizon

0-15 cm	ochric A horizon
15-140 cm	argillic B horizon
-	ferric

Local classification:	Argillic yellow soil; Hapli-Perudic Argosol
Common name:	Yellow claypan soil

Other classification

USDA-NRCS (1999)	Typic Hapludult
USDA-SCS (1975)	Typic Hapludult perudic clayey mixed mesic

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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	-	1.2	1.3	1.3	1.4	1.1	6.3	5.6	30.3	35.9	57.8
15-50	-	0.2	0.1	0.2	0.4	0.8	1.7	2.1	29.0	31.1	67.3
50-110	-	0.1	0.4	1.0	1.5	0.7	3.7	3.0	33.7	36.7	59.6
110-140	-	0.1	0.5	1.5	2.4	1.2	5.7	2.8	38.9	41.7	52.8
140-140	-	0.1	0.7	1.7	2.6	0.9	6.0	5.3	41.3	46.6	47.3

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	1.261	-	-	-	57.8
15-50	1.090	-	-	-	67.3
50-110	1.083	-	-	-	59.6
110-140	-	-	-	-	52.8
140-140	-	-	-	-	47.3

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
0-15	1.261	55.7	54.2	51.7	47.7	45.5	43.3	41.9	37.3
15-50	1.090	62.4	60.6	59.7	58.4	57.8	57.0	49.2	44.2
50-110	1.083	64.2	64.0	63.4	62.7	62.2	61.6	50.1	45.6

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
0-15	4.9	4.1	0.08	-	1.92	0.19	10	8.6	6.9	4.3	1.4	0.4	0.2	6.3
15-50	5.1	4.0	0.03	-	0.56	0.09	6	9.8	8.1	2.9	0.7	0.2	0.0	3.8
50-110	5.3	4.1	0.01	-	0.29	0.05	6	10.6	8.2	2.8	0.7	0.2	0.2	3.9
110-140	5.4	4.1	0.04	-	0.16	0.06	3	10.4	8.7	1.3	0.4	0.2	0.2	2.1
140-140	5.3	4.0	0.04	-	0.15	0.06	3	10.6	8.5	1.2	0.3	0.3	0.1	1.9

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	38	16.8	29	6.7	-	41	1
15-50	26	14.7	22	2.0	-	55	0
50-110	22	17.6	30	1.0	-	47	1
110-140	14	14.6	28	0.6	-	60	1
140-140	12	15.4	33	0.5	-	55	1

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	-	8.4	8.8	-	-	-	-	-	-
15-50	-	0.0	1.6	-	-	-	-	-	-
50-110	-	0.0	0.4	-	-	-	-	-	-
110-140	-	0.0	1.8	-	-	-	-	-	-
140-140	-	0.0	1.9	-	-	-	-	-	-

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-15	-	-	-	weak	-	-	medium to strong	weak	medium to strong	-	weak	weak
15-50	-	-	-	weak	-	-	medium to strong	weak	medium to strong	-	weak	weak
50-110	-	-	-	medium to strong	-	-	medium to strong	medium to strong	medium to strong	-	weak	weak
110-140	-	-	-	medium to strong	-	-	medium to strong	medium to strong	medium to strong	-	weak	weak
140-140	-	-	-	medium to strong	-	-	medium to strong	medium to strong	medium to strong	-	weak	weak

Profile description

Ah 0-15 cm	dark yellowish brown (10YR 4/4, moist)clay,moderate fine subangular blocky to moderate medium granular,firm,common very fine inped pores highly porous (>60 vol%),very few small irregular hard unspecified unspecified inclusions very few small irregular soft unspecified unspecified inclusions,frequent pedotubules,abrupt smooth boundary to,
Bt1 15-50 cm	strong brown (7.5YR 5/8, moist)clay,moderate to strong fine and medium subangular blocky,firm,continuous clay and humus on pedfaces cutans,many very fine inped pores and common inped pores highly porous (>60 vol%),few pedotubules,abrupt smooth boundary to,
Bt2 50-110 cm	strong brown (7.5YR 5/8, moist)clay,moderate to strong fine and medium subangular blocky to moderate to strong medium columnar,friable,continuous clay and humus in root channels and pores cutans,many very fine inped pores and common inped pores highly porous (>60 vol%),few pedotubules,clear wavy boundary to,
110-140 cm	reddish yellow (7.5YR 6/8, moist)silty clay,moderate medium columnar,very friable non sticky,common medium distinct sharp mottles (7.5YR 6/8),broken clay and humus in root channels and pores cutans,many very fine inped pores and many inped pores highly porous (>60 vol%),clear boundary to,
C 140- cm	yellow (10YR 7/6, moist)silty clay,weak to moderate medium columnar to weak to moderate medium subangular blocky,very friable non sticky,many very fine inped pores and many inped pores moderately porous (40-60 vol%),

Kind 1 (parent material) ; Parker (eds), 1984	shale
Mode of accumulation or deposition of parent material	residual material
Remarks on Parent Materials	more than 2.5m depth
Soil Depth	150cm
General characterization of the status of weathering of solid rock	slightly

Occurrence of soil aggradation (McDonald et al., 1984)	absent
Intensity of the soil erosion type	slight
Intensity of the soil erosion type (second entry)	slight
Soil erosion type	sheet
Soil erosion type (second entry)	rill
Slope stability	stable

Major crops	tea
Land use or vegetation in the immediate vicinity of the site	low level arable farming
Remarks on Land Use / Vegetation	LANDUSE: Undergrowth of grasses eaten by cattle

Altitude	1230m
Physiographic Unit	lower hill, Pingba Basin
Physiographic position of the site	upper slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	low hill
Slope	2%
Slope Aspect	north
Form of the slope surrounding the site	convex
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	0-110cm
Estimated run off (class)	medium
Wet From To	110-150cm

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Average size of stone	15
Surface cracking	no cracks observed
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	no surface slaking/crusting observed
Microrelief Height: variation in height	10
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	knobs
Rock outcrop class (FAO (2006) - Guidelines for soil description)	none
Evidence of salt; Soil Survey Manual USDA, 1951	non-saline
Shape of stones (on average)	platy or flat
Surface stoniness class (FAO (2006) - Guidelines for soil description)	very few stones

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Reference soil China 47: Alisol

Characteristics

Reference soil CN047: Alisols

Classification