Reference soil China 35: Phaeozem

CN035

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 CN035: Phaeozems

PROFILE DESCRIPTION : Deep, well drained, very dark grayish brown clay loam overlying a strongly mottled, slightly altered subsoil. The soil is derived from alluvial deposits and has a fluctuating groundwater level which reached to about 120 cm below the surface. The general structure is crumb, however, angular blocky structures dominate on the surface horizons. A plough pan has formed below the arable surface layer. The soil has a medium content in organic matter and a neutral reaction. CLIMATE: climatic data regarding sunshine hours per month: J 187.2 F 192.3 M 233.4 A 236.3 M 244.9 J 251.2 J 208.5 A 227.9 S 236.1 O 208.5 N 180.2 D 174.3 Year 2570.0

Classification

WRB 2006

WRB 1998

Haplic- Phaeozem (Pachic Siltic)

Silti-Pachic- Phaeozem

0-120 cm

mollic horizon

0-120 cm

mollic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Silti-Haplic Phaeozem phreatic

Haplic Phaeozem phreatic

0-120 cm	mollic A horizon
- cm	mollic A horizon

0-120 cm

mollic A horizon

Local classification:	Haplic thermo-black soil; Hapli-Udic Isohumosol
Common name:	Black earth

Other classification

USDA-NRCS (1999)	Cumulic Hapludoll
USDA-SCS (1975)	Cumulic Hapludoll udic 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
5-20	-	0.3	0.3	0.3	0.4	6.7	8	29.2	32.7	61.9	30.0
25-35	-	0.2	0.1	0.1	0.1	3.7	4.2	23.5	31.1	54.6	41.4
40-65	-	0.1	0.1	0.2	0.4	9.0	9.8	31.9	25.6	57.5	32.7
80-100	-	0.1	0.1	0.1	0.2	7.2	7.7	28.2	25.7	53.9	38.5
125-140	-	0.1	0.1	0.0	0.4	10.8	11.4	29.8	24.7	54.5	33.9

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
15-20	1.288	-	-	-	-
5-20	-	-	-	-	30.0
50-55	1.351	-	-	-	-
25-35	-	-	-	-	41.4
40-65	-	-	-	-	32.7
80-85	1.279	-	-	-	-
80-100	-	-	-	-	38.5
125-140	-	-	-	-	33.9

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
15-20	1.288	47.0	43.5	38.7	34.5	34.1	30.7	28.7	20.7
50-55	1.351	45.4	44.6	42.0	39.2	38.8	35.5	29.4	19.3
80-85	1.279	47.2	46.0	42.6	40.1	39.7	36.4	31.0	22.3

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
5-20	6.3	5.4	0.21	-	1.19	0.14	8	-	-	19.1	4.5	0.6	0.2	24.4
25-35	6.8	5.5	0.08	1.2	1.14	0.12	10	-	-	22.2	6.0	0.6	0.1	28.9
40-65	7.0	5.7	0.07	1.1	1.14	0.10	11	-	-	20.7	5.6	0.4	0.1	26.8
80-100	7.0	5.8	0.09	1.2	1.07	0.10	11	-	-	24.6	7.4	0.5	0.2	32.7
125-140	7.0	5.4	0.07	1.2	0.29	0.04	7	-	-	18.6	5.9	0.4	0.2	25.1

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 %
5-20	101	24.1	80	4.2	-	-	1
25-35	105	27.4	66	4.0	-	-	0
40-65	109	24.7	76	4.0	-	-	0
80-100	110	29.8	77	3.7	-	-	1
125-140	105	23.8	70	1.0	-	-	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
5-20	-	-	44.5	-	-	-	-	-	-
25-35	-	-	4.6	-	-	-	-	-	-
40-65	-	-	9.1	-	-	-	-	-	-
80-100	-	-	16.2	-	-	-	-	-	-
125-140	-	-	19.0	-	-	-	-	-	-

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
5-20	-	-	-	-	-	-	weak	weak	weak	weak	medium to strong	weak
25-35	-	-	-	-	-	-	weak	weak	weak	weak	medium to strong	weak
40-65	-	-	-	-	-	-	weak	weak	weak	weak	medium to strong	weak
80-100	-	-	-	-	-	-	weak	weak	weak	weak	medium to strong	weak
125-140	-	-	-	-	-	-	weak	weak	weak	weak	medium to strong	weak

Profile description

Ap1 0-25 cm	dark brown (7.5YR 3/2, moist)loam,weakly coherent porous massive and moderate very fine and fine angular blocky,slightly hard very friable sticky plastic,no cutans,many very fine interstitial pores and many tubular pores,no inclusions,no fragments,non-cemented pans,abrupt smooth boundary to,
Ap2 25-35 cm	very dark greyish brown (10YR 3/2, moist)clay loam,moderate medium crumb and moderate fine angular blocky,friable slightly sticky plastic,no cutans,many very fine interstitial pores and many tubular pores,no inclusions,no fragments,discontinuous non-cemented plough pan pans,clear smooth boundary to,
Ah1 35-72 cm	very dark greyish brown (10YR 3/2, moist)clay loam,weakly coherent porous massive parting to weak medium crumb,friable slightly sticky plastic,many very fine fine interstitial pores and many fine tubular pores moderately porous (40-60 vol%),diffuse smooth boundary to,
Ah2 72-120 cm	very dark greyish brown (10YR 3/2, moist)clay loam,weakly coherent porous massive parting to weak medium crumb,friable slightly sticky plastic,many very fine fine interstitial pores and few medium continuous exped and inped tubular vertical pores moderately porous (40-60 vol%),gradual smooth boundary to,
Cg 120-150 cm	yellowish brown (10YR 5/6, moist)clay loam,weak to moderate porous massive parting to moderate fine angular blocky,very friable slightly sticky slightly plastic,many coarse faint clear mottles (2.5Y 3/3) and common medium faint mottles (2.5Y 5/8),no cutans,many very fine fine tubular pores,

Kind 1 (parent material) ; Parker (eds), 1984	sediment, unconsolidated
Mode of accumulation or deposition of parent material	fluvial
Soil Depth	120cm

Major crops	maize
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	medium level arable farming
Remarks on Land Use / Vegetation	VEGETATION: see additional remarks
Rotation scheme ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	continuous crop rotation

Altitude	50m
Physiographic Unit	higher part of alluvial plain
Physiographic position of the site	flat
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	alluvial plain
Slope	1%
Form of the slope surrounding the site	straight
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	flat or almost flat

Drainage class ; FAO (2006) - Guidelines for soil description	well
Flooding frequency (FAO, 1986)	irregular
Nature of flood water	fresh
(Estimated) maximum (lower) depth to groundwater table	0cm
Depth to groundwater table	155cm
Kind of ground water table (USDA, 1979)	perched
(Estimated) minimum (upper) depth to groundwater table	120cm
Moist From - To	0-120cm
Estimated permeability (class) of least permeable part of the profile	slow
Estimated run off (class)	medium

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)	surface partly slaked, round smooth aggregates
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	level
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 35: Phaeozem

Characteristics

Reference soil CN035: Phaeozems

Classification