Reference soil China 31: Nitisol

CN031

Nitisols occur mainly in the tropics and subtropics, as well as in areas with a Mediterranean type of climate. They are associated with basic rocks (e.g. basalts) or hard limestone or dolomite deposits.

Characteristics

Soils having a nitic horizon (a horizon with pronounced nut-shaped soil structure and significant amount of active iron) within 100 cm from the soil surface, and gradual to diffuse horizon boundaries between the surface and the underlying horizons. They do not have a ferric, plinthic or vertic horizon within 100 cm from the soil surface.

Distribution of Nitisols (rough estimation supplied by soilgrids)

Reference soil CN031: Nitisols

PROFILE DESCRIPTION : Deep, well drained, dark reddish brown clay derived from grey marble. The thin but dark coloured topsoil has a strongly developed subangular blocky structure, while in the remaining soil strong angular blocky structures prevail. The organic carbon content is medium, averaged over the first 25 cm. Soil reaction is acid in the first 50 cm, becoming slichtly acid below and neutral to slightly alkaline near the only slightly altered rock. GENERAL LANDFORM: steep mountains (tower karst-like) with a great variety in soil depth. Rock outcrops occur alongside deep soils. In the soil great boulders of marble occur. They have a typical solution surface with smooth curves. The soil itself doesn't seem to have free carbonates. The lower slope has hardly any colluvial material and the is a sharp transition from the straight slope to the flat intermontane basin / SOILS: apart from the dominant red coloured soils some browner ones occur on the lower slopes. Also a violet B horizon was found next to a red soil. Apart from an irregular depth also the content of stones varies from place to place. Slide nos. of the ISRIC collection: 13934-13944 (landscape, profile, profile details, monolith taking).

Classification

WRB 2006

WRB 1998

Ferralic- Nitisol (Rhodic)

Eutric- Nitisol

5-120 cm	nitic horizon
-	ferralic

0-5 cm	ochric horizon
5-120 cm	nitic horizon
-	ferralic

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Eutri-Rhodic Nitisol

Chromic Luvisol

0-5 cm	ochric A horizon
- cm	argic B horizon
- cm	ochric A horizon
-	nitic

0-5 cm	ochric A horizon
24-120 cm	argillic B horizon

Local classification:	Luvic brown limestone soil; Ferri-Udic Argosol
Common name:	Red granular clay

Other classification

USDA-NRCS (1999)	Typic Hapludalf
USDA-SCS (1975)	Typic Hapludalf 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
0-5	-	1.8	2.1	2.5	5.0	5.8	17.2	9.4	27.8	37.2	45.6
10-20	-	3.6	2.2	2.4	5.1	3.7	17	10.9	19.7	30.6	52.4
25-50	-	1.9	1.5	1.7	3.4	4.1	12.6	8.4	22.3	30.7	56.7
55-75	-	5.3	2.9	2.4	4.2	3.1	17.9	7.1	19.5	26.6	55.7
90-110	-	4.8	3.0	2.1	3.4	3.9	17.2	7.4	17.9	25.3	57.4
130-165	-	8.6	12.2	6.9	4.4	1.2	33.3	8.5	19.1	27.6	39.1

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-5	-	-	-	16.5	45.6
15-20	1.351	-	-	-	-
10-20	-	-	-	29.8	52.4
35-40	1.309	-	-	-	-
25-50	-	-	-	35.8	56.7
90-95	1.532	-	-	-	-
55-75	-	-	-	37.2	55.7
90-110	-	-	-	32.8	57.4
130-165	-	-	-	34.7	39.1

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	1.351	45.7	43.8	40.1	36.9	35.9	34.4	32.7	28.4
35-40	1.309	43.4	41.0	37.0	34.2	33.3	31.8	31.3	26.8
90-95	1.532	40.9	40.3	39.6	37.6	36.7	35.5	31.1	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
0-5	6.1	5.7	0.20	-	4.22	0.34	12	0	0	20.1	1.0	0.3	0.0	21.4
10-20	4.9	4.0	0.06	-	1.60	0.17	9	1.4	1.1	7.6	0.3	0.1	0.0	8
25-50	5.2	4.1	0.03	-	0.80	0.13	6	0.7	0.5	8.0	0.0	0.1	0.0	8.1
55-75	5.5	4.6	0.02	-	0.71	0.13	5	0.1	0	10.1	0.0	0.1	0.0	10.2
90-110	5.9	5.0	0.03	-	0.65	0.11	6	0	0	10.9	0.0	0.1	0.0	11
130-165	7.6	6.8	0.20	2.3	0.71	0.12	6	0	0	41.6	0.3	0.1	0.2	42.2

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 %
0-5	86	24.8	54	14.8	-	0	0
10-20	49	16.3	31	5.6	-	7	0
25-50	51	15.8	28	2.8	-	3	0
55-75	68	14.9	27	2.5	-	0	0
90-110	71	15.4	27	2.3	-	0	0
130-165	201	21.0	169	2.5	-	0	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
0-5	-	-	-	0.26	0.01	2.50	0.40	-	-	-	0.55
10-20	-	-	-	0.27	0.00	2.70	0.50	-	-	-	0.43
25-50	-	-	-	0.29	0.02	3.10	0.50	-	-	-	0.41
55-75	-	-	-	0.27	0.00	2.90	0.40	-	-	-	0.34
90-110	-	-	-	0.25	0.01	3.00	0.50	-	-	-	0.41
130-165	-	-	-	0.25	0.03	3.60	0.50	-	-	-	0.43

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
0-5	-	0.7	-	-	-	-	-	-	-
10-20	-	0.1	-	-	-	-	-	-	-
25-50	-	0.0	-	-	-	-	-	-	-
55-75	-	0.1	-	-	-	-	-	-	-
90-110	-	0.0	-	-	-	-	-	-	-
130-165	-	0.0	-	-	-	-	-	-	-

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-5	strong	-	-	weak	-	-	medium to strong	-	-	-	-	very weak
10-20	strong	-	-	weak	-	-	medium to strong	-	-	-	-	very weak
25-50	strong	-	-	weak	-	-	medium to strong	-	-	-	-	very weak
55-75	strong	-	-	weak	-	-	medium to strong	-	-	-	-	very weak
90-110	strong	-	-	weak	-	-	medium to strong	-	-	-	-	very weak
130-165	weak	-	-	weak	-	-	strong	medium to strong	-	-	-	medium to strong

Profile description

Ah 0-5 cm	(dark) brown (10YR 4/3, dry) dark brown (10YR 3/3, moist)clay loam slightly gravelly,strong very fine and fine subangular blocky,very hard very firm sticky plastic,common fine medium continuous exped vesicular random pores highly porous (>60 vol%),very few fine gravel fresh marble fragments,frequent worm channels and coprogenic elements,clear smooth boundary to,
5-24 cm	strong brown (7.5YR 4/6, dry) dark yellowish brown (10YR 4/6, moist)clay slightly gravelly,moderate to strong medium and coarse angular blocky parting to strong fine and medium angular blocky,extremely hard very firm very sticky very plastic,patchy thin clay on pedfaces cutans,common fine continuous inped tubular random pores moderately porous (40-60 vol%),very few medium gravel fresh marble fragments,frequent worm channels,gradual smooth boundary to,
Bt1 24-51 cm	dark yellowish brown (10YR 3/6, dry) dark yellowish brown (10YR 3/4, moist)clay slightly stony,very strong coarse angular blocky parting to strong fine and medium angular blocky,extremely hard very firm very sticky very plastic,continuous thick clay on pedfaces cutans,few very fine fine continuous inped tubular random pores slightly porous (<40 vol%),few medium gravel fresh marble fragments,few worm channels,gradual smooth boundary to,
Bt2 51-120 cm	dark yellowish brown (10YR 3/6, moist)clay bouldery,very strong coarse angular blocky parting to strong fine and medium angular blocky,very firm very sticky very plastic,continuous thick clay on pedfaces cutans,few very fine fine continuous inped tubular random pores slightly porous (<40 vol%),few coarse gravel and stones fresh marble fragments,few worm channels,
Auger 120-165 cm	dark yellowish brown (10YR 3/6, moist)clay bouldery,very firm very sticky very plastic,slightly porous (<40 vol%),

Kind 1 (parent material) ; Parker (eds), 1984	limestone
Mode of accumulation or deposition of parent material	residual material
Remarks on Parent Materials	gray marble
Soil Depth	165cm
Texture of parent material	clayey
Texture of parent material (second entry)	clayey
Weathering Resistance	very high
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	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: Some isolated fir and pine trees
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)	degraded
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	evergreen shrub

Altitude	250m
Physiographic Unit	tower karst mountains
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.	mountain
Slope	100%
Slope Aspect	east-north-east
Form of the slope surrounding the site	straight
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	mountainous

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	50-165cm
Estimated permeability (class) of least permeable part of the profile	high
Estimated run off (class)	slow

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Average size of stone	10
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)	rocky
Evidence of salt; Soil Survey Manual USDA, 1951	non-saline
Shape of stones (on average)	(sub-)rounded
Surface stoniness class (FAO (2006) - Guidelines for soil description)	very few stones

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Reference soil China 31: Nitisol

Characteristics

Reference soil CN031: Nitisols

Classification