Reference soil China 49: Phaeozem

CN049

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 CN049: Phaeozems

PROFILE DESCRIPTION : Moderately deep, somewhat excessively drained, reddish brown clay developed derived from limestone which highly fluctuates with depth. GENERAL SOIL INFORMATION: the steeply rising limestone hills being part of the Pingba basin show a completely other soil profile and land use than the lower hills with yellow soils developed from shale (CN047) and Quaternary clay (CN048). The influencing factor is the parent material which as weathered material gives rise to a Rendzina-like profile. However, due to the great soil depth of profile CN049 and the presence of an argic B horizon, the soil is classified as a Luvic Phaeozem (FAO, 1988). The second layer of the profile is classified as a Bw horizon because of a change in colour and structure.

Classification

WRB 2006

WRB 1998

Luvic-Ferralic- Phaeozem (Clayic Chromic)

Chromi-Luvic- Phaeozem

35-140 cm	argic horizon
-	ferralic

0-35 cm	mollic horizon
35-140 cm	argic horizon
-	ferralic

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Chromi-Luvic Phaeozem rudic

Luvic Phaeozem stony

0-35 cm	mollic A horizon
- cm	argic B horizon
- cm	mollic A horizon

0-35 cm	mollic A horizon
35-115 cm	argillic B horizon

Local classification:	Haplic brown limestone soil; Isohumisol
Common name:	Black earth

Other classification

USDA-NRCS (1999)	Typic Argiudoll
USDA-SCS (1975)	Typic Argiudoll perudic very fine mixed mesic

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
0-35	-	2.2	2.1	2.0	2.1	2.0	10.4	6.8	37.0	43.8	45.8
35-115	-	1.2	1.3	1.4	1.6	1.5	7	2.1	20.9	23.0	70.0
115-140	-	1.2	1.2	1.3	1.5	1.5	6.7	3.1	20.4	23.5	69.7

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-35	1.148	-	-	-	45.8
35-115	1.193	-	-	-	70.0
115-140	1.257	-	-	-	69.7

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
0-35	1.148	56.9	56.1	53.2	48.6	45.3	41.5	38.3	32.6
35-115	1.193	54.7	53.5	51.5	49.9	49.0	48.0	38.9	35.2
115-140	1.257	56.5	55.5	54.8	53.8	53.0	52.3	44.2	42.1

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
0-35	6.5	6.2	0.20	4.8	3.66	0.44	8	-	-	29.3	10.3	0.3	0.2	40.1
35-115	7.0	6.3	0.14	1.1	1.07	0.15	7	-	-	13.8	8.2	0.3	0.2	22.5
115-140	7.4	6.3	0.14	1.5	0.76	0.11	7	-	-	15.5	8.5	0.4	0.2	24.6

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 %
0-35	119	33.7	74	12.8	-	-	1
35-115	115	19.5	28	3.7	-	-	1
115-140	120	20.5	29	2.7	-	-	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
0-35	-	0.8	2.0	-	-	-	-	-	-
35-115	-	0.0	0.6	-	-	-	-	-	-
115-140	-	0.0	0.6	-	-	-	-	-	-

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-35	medium to strong	-	-	very weak	-	-	medium to strong	weak	weak	weak	-	-
35-115	medium to strong	-	-	very weak	-	-	medium to strong	weak	weak	weak	-	-
115-140	medium to strong	-	-	weak	-	-	medium to strong	weak	medium to strong	-	-	-

Profile description

Ah 0-35 cm	(7.5YR 3/3, moist)silty clay gravelly,strong fine and medium granular and strong fine subangular blocky,very friable,many very fine inped pores highly porous (>60 vol%),frequent medium gravel fresh limestone fragments,frequent worm channels,clear wavy boundary to,
B 35-115 cm	dark yellowish brown (10YR 4/4, moist)clay,moderate to strong medium subangular blocky,friable,patchy humus in root channels and pores cutans,common very fine inped pores and common inped pores moderately porous (40-60 vol%),very few medium gravel fresh limestone fragments,gradual wavy boundary to,
C 115-140 cm	brown (10YR 5/3, moist)clay,moderate to strong fine subangular blocky parting to moderate to strong fine and medium columnar,firm,common micro pores moderately porous (40-60 vol%),frequent fine gravel strongly weathered weath.limestone fragments,clear wavy boundary to,
C 115-140 cm	pale brown (10YR 6/3, dry)

Kind 1 (parent material) ; Parker (eds), 1984	limestone
Mode of accumulation or deposition of parent material	residual material
Remarks on Parent Materials	depth fluctuates
Soil Depth	90cm
Texture of parent material	clayey
General characterization of the status of weathering of solid rock	partially or moderately

Occurrence of soil aggradation (McDonald et al., 1984)	absent
Intensity of the soil erosion type	slight
Soil erosion type	sheet
Slope stability	locally unstable

Land use or vegetation in the immediate vicinity of the site	non-agricultural land
Remarks on Land Use / Vegetation	LANDUSE: Maize/soybeans/sunfower at 30m distance
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)	short grassland

Altitude	1290m
Physiographic Unit	limestone hill, Pingba Basin
Physiographic position of the site	lower slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	hill
Slope	7%
Slope Aspect	north-west
Form of the slope surrounding the site	straight
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	steeply dissected

Drainage class ; FAO (2006) - Guidelines for soil description	somewhat excessive
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Moist From - To	0-140cm
Estimated run off (class)	medium
Drainage class - intergrade; FAO (2006) - Guidelines for soil description	excessive

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Average size of stone	7
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	50
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	knobs
Microrelief pattern	isolated
Rock outcrop class (FAO (2006) - Guidelines for soil description)	extremely rocky
Evidence of salt; Soil Survey Manual USDA, 1951	non-saline
Shape of stones (on average)	angular irregular
Surface stoniness class (FAO (2006) - Guidelines for soil description)	exceedingly stony

You are here

Reference soil China 49: Phaeozem

Characteristics

Reference soil CN049: Phaeozems

Classification