Reference soil China 32: Ferralsol

CN032

Ferralsols occur in tropical and subtropical regions of the world, mainly on old and stable land surfaces.

Characteristics

Soils having a ferralic horizon (strongly weathered horizon with low-activity clays and very low amounts of weatherable minerals) between 25 and 200 cm from the soil surface. They lack a nitic horizon (a horizon with strongly developed, nut-shaped structure) and do not have a layer which fulfils the requirements of an argic horizon and which has, in the upper 30 cm, 10 percent or more water-dispersible clay.

Distribution of Ferralsols (rough estimation supplied by soilgrids)

Reference soil CN032: Ferralsols

PROFILE DESCRIPTION :Deep, well drained, dak brown to yellowish red gravelly clay derived from biotite granite covered by a dark (yellowish) brown colluvial layer of about 20 cm thick. The colluvial layer has a high content in organic carbon and exhibits weakly to moderately developed subangular blocky structures. The subsoil dominantly has moderately to strongly developed medium angular blocky structures. The buried A horizon still has a medium content in organic carbon. Soil reaction is strongly acid throughout. GENERAL LANDFORM: rounded hills with a convex slope form. Hardly any accumulation of material on the lower slope. Therefore a sharp knickpoint towards the flat valley floors / SOILS: about 20cm of colluvial material occurs at the surface. A fully developed Ah horizon is present in this material. There is no clear reason why this colluvium is present. Slide nos. of the ISRIC collection: 13945-13950 (landscape, profile, profile details).

Classification

WRB 2006

WRB 1998

Acric- Ferralsol (Colluvic Alumic Clayic)

Alumi-Acric- Ferralsol

36-130 cm

ferralic horizon

0-20 cm	ochric horizon
36-130 cm	ferralic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Alumi-Ferralic Cambisol

Orthic Ferralsol

0-36 cm	ochric A horizon
- cm	cambic B horizon
- cm	ochric A horizon
-	ferralic

0-36 cm	ochric A horizon
55-120 cm	oxic B horizon

Local classification:	Haplic latored soil; Hapli-Udic Ferralosol

Other classification

USDA-NRCS (1999)	Typic Hapludox
USDA-SCS (1975)	Typic Haplorthox udic clayey kaolinitic thermic

More images

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
0-8	-	11.9	16.8	9.4	6.0	1.6	45.7	1.2	16.7	17.9	36.2
8-20	-	15.1	13.1	7.3	4.8	2.1	42.4	2.0	15.6	17.6	40.1
20-36	-	9.2	11.2	7.6	5.3	1.8	35.1	0.7	16.7	17.4	47.6
36-55	-	12.7	14.6	8.2	5.1	2.3	42.9	2.0	14.8	16.8	40.3
55-75	-	18.0	9.6	5.1	3.6	1.4	37.7	2.6	12.8	15.4	47.0
90-120	-	14.1	8.0	4.7	3.9	2.6	33.3	2.9	15.0	17.9	48.7
140-160	-	12.1	13.2	10.3	10.7	4.3	50.6	6.7	17.8	24.5	24.9
200-220	-	14.4	19.5	13.7	11.2	6.8	65.6	7.1	16.9	24.0	10.4

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
60-65	1.293	-	-	-	-
0-8	-	-	-	-	36.2
8-20	-	-	-	-	40.1
20-36	-	-	-	-	47.6
36-55	-	-	-	-	40.3
55-75	-	-	-	-	47.0
90-120	-	-	-	-	48.7
140-160	-	-	-	-	24.9
200-220	-	-	-	-	10.4

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
60-65	1.293	45.9	43.2	39.0	36.0	35.0	33.7	33.7	29.0

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
0-8	4.3	3.8	0.08	-	2.91	0.23	13	3.5	3.2	0.8	0.3	0.3	0.0	1.4
8-20	4.3	3.9	0.04	-	1.36	0.09	15	3.8	3.6	0.4	0.0	0.1	0.0	0.5
20-36	4.3	4.0	0.02	-	0.96	0.09	11	3.3	3.2	0.2	0.0	0.2	0.0	0.4
36-55	4.4	3.9	0.02	-	0.58	0.07	8	3.6	3.4	0.2	0.0	0.2	0.0	0.4
55-75	4.5	3.9	0.02	-	0.48	0.06	8	3.3	3.2	0.2	0.0	0.2	0.0	0.4
90-120	4.6	4.0	0.01	-	0.39	0.05	8	3.6	3.4	0.2	0.0	0.2	0.0	0.4
140-160	4.5	4.0	0.01	-	0.12	0.02	6	6.8	6.2	0.2	0.0	0.1	0.0	0.3
200-220	4.8	4.0	0.01	-	0.04	0.01	4	7.4	5.7	0.2	0.0	0.1	0.1	0.4

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 %
0-8	13	10.5	29	10.2	-	30	0
8-20	7	6.9	17	4.8	-	52	0
20-36	6	6.9	14	3.4	-	46	0
36-55	6	6.9	17	2.0	-	49	0
55-75	6	6.9	15	1.7	-	46	0
90-120	6	6.9	14	1.4	-	49	0
140-160	3	8.8	35	0.4	-	70	0
200-220	4	9.4	90	0.1	-	61	1

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
0-8	-	-	-	-	-	1.40	0.20	-	-	-	-
8-20	-	-	-	-	-	1.50	0.20	-	-	-	-
20-36	-	-	-	-	-	1.40	0.30	-	-	-	-
36-55	-	-	-	-	-	1.50	0.30	-	-	-	-
55-75	-	-	-	-	-	1.50	0.30	-	-	-	-
90-120	-	-	-	-	-	1.60	0.30	-	-	-	-
140-160	-	-	-	-	-	1.70	0.30	-	-	-	-
200-220	-	-	-	-	-	0.70	0.10	-	-	-	-

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
0-8	-	3.0	-	-	-	-	-	-	-
8-20	-	0.0	-	-	-	-	-	-	-
20-36	-	0.0	-	-	-	-	-	-	-
36-55	-	0.0	-	-	-	-	-	-	-
55-75	-	0.0	-	-	-	-	-	-	-
90-120	-	0.0	-	-	-	-	-	-	-
140-160	-	0.0	-	-	-	-	-	-	-
200-220	-	0.0	-	-	-	-	-	-	-

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-8	weak	-	very weak	very weak	-	-	very strong	weak	-	-	-	-
8-20	weak	-	very weak	very weak	-	-	very strong	weak	-	-	-	-
20-36	weak	-	very weak	very weak	-	-	very strong	weak	-	-	-	-
36-55	weak	-	very weak	very weak	-	-	very strong	weak	-	-	-	-
55-75	weak	-	very weak	very weak	-	-	very strong	weak	-	-	-	-
90-120	weak	-	very weak	very weak	-	-	very strong	weak	-	-	-	-
140-160	weak	-	very weak	very weak	-	-	strong	weak	-	-	weak	-
200-220	-	-	very weak	very weak	-	-	medium to strong	weak	-	-	medium to strong	-

Profile description

Ah 0-8 cm	yellowish brown (10YR 5/4, dry) dark yellowish brown (10YR 4/6, moist)sandy clay loam slightly gravelly leaves nil,weak to moderate medium subangular blocky,very hard friable slightly sticky slightly plastic,many fine to coarse continuous exped and inped vesicular random pores highly porous (>60 vol%),frequent worm channels,clear wavy boundary to,
8-20 cm	strong brown (7.5YR 4/6, dry) (dark) brown (7.5YR 4/4, moist)sandy clay gravelly,moderate medium subangular blocky,hard firm sticky plastic,no cutans,common fine very fine continuous exped and inped tubular random pores moderately porous (40-60 vol%),frequent worm channels,clear smooth boundary to,
2Ah 20-36 cm	dark yellowish brown (10YR 4/4, dry) dark yellowish brown (10YR 3/4, moist)sandy clay gravelly,moderate medium and coarse subangular blocky,very hard friable sticky plastic,no cutans,many fine to coarse continuous exped and inped tubular random pores highly porous (>60 vol%),frequent worm channels,clear wavy boundary to,
36-55 cm	strong brown (7.5YR 5/6, dry) strong brown (7.5YR 4/6, moist)clay gravelly,moderate medium angular blocky,very hard firm very sticky very plastic,patchy thin clay on pedfaces cutans,common fine very fine continuous exped and inped tubular random pores and few continuous exped and inped tubular random pores highly porous (>60 vol%),few channels,gradual smooth boundary to,
2Bt1 55-75 cm	yellowish brown (10YR 5/6, moist)clay gravelly,moderate to strong medium angular blocky,firm very sticky very plastic,broken thin clay on pedfaces cutans,common fine very fine continuous exped and inped tubular random pores and few continuous exped and inped tubular random pores moderately porous (40-60,few channels,gradual smooth boundary to,
2Bt2 75-130 cm	yellowish brown (10YR 5/8, moist)clay very gravelly,moderate to strong fine and medium angular blocky,firm very sticky very plastic,continuous moderately thick clay on pedfaces cutans,common fine very fine continuous exped and inped tubular random pores moderately porous (40-60 vol%),manganiferous,clear irregular boundary to,
2Bt2 75-130 cm	yellow (10YR 7/8, moist)

Depth1	20cm
Kind 1 (parent material) ; Parker (eds), 1984	sediment, unconsolidated
Kind 2 (parent material) (second entry); Parker (eds), 1984	coarse-grained acid igneous rock
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	biotite granite
Soil Depth	130cm
Texture of parent material	loamy
Texture of parent material (second entry)	sandy clay
Weathering Resistance	moderate
Weathering Resistance (second entry)	poor
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)	present
Intensity of the soil erosion type	slight
Soil erosion type	sheet
Slope stability	stable

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: Bamboo, Masson pine, Chinese fir
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)	evergreen forest

Altitude	250m
Physiographic Unit	rounded hills
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	25%
Slope Aspect	south-west
Form of the slope surrounding the site	convex
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	steeply dissected

Drainage class ; FAO (2006) - Guidelines for soil description	well
Dry From - To	0-50cm
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	50-250cm
Estimated permeability (class) of least permeable part of the profile	high
Estimated run off (class)	medium

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

You are here

Reference soil China 32: Ferralsol

Characteristics

Reference soil CN032: Ferralsols

Classification