Reference soil Mozambique 09: Solonetz

MZ009

Solonetzes occur where a sodium source supplies the clay-rich subsoil with exchangeable Na, causing peptization of clay and organic substances and deterioration of the topsoil.

Characteristics

Soils having a natric horizon (a subsurface horizon with distinct higher clay content than the overlying horizon and more than 15% exchangeable sodium) within 100 cm from the soil surface.

Distribution of Solonetz (rough estimation supplied by soilgrids)

Reference soil MZ009: Solonetz

PHYSIOGRAPHY: Slope length: - 200 m. Termite mounds: - inactive, 4/ha, 20-50 cm high, 5-15 m across, with concentration of vegetation. Surface characteristics: - 1 mm soft crust, below 3-4 cm rather compact. - surface is covered by quartz grains. Surface drainage: - hardly existent, only fossile drainage system. VEGETATION AND LAND USE: coverage(%) regional local Shrubs 5 2 Herbs 5 5 Grasses 45-65 60 Bare ground 30-50 35 SOIL FAUNA: - insect nests. ADDITIONAL NOTES ON PROFILE DESCRIPTION: Bt - consistency dry: also extremely hard. - cutans: also moderately thick. - roots: along ped faces. - tonguing along cracks of not very bleached quartz grains. BC - pockets of not very bleached quartz grains.

Classification

WRB 2006

WRB 1998

Haplic- Solonetz (Abruptic Magnesic)

Magnesic- Solonetz

16-50 cm	argic horizon
50-75 cm	natric horizon
-	abrupt textural change

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Abrupti-Haplic Solonetz

Orthic Solonetz

0-16 cm	ochric A horizon
16-50 cm	argic B horizon
50-75 cm	natric B horizon
-	abrupt textural change

0-16 cm	ochric A horizon
16-50 cm	argillic B horizon
50-75 cm	natric B horizon
-	abrupt textural change

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
0-16	-	5.1	16.7	20.7	23.2	10.9	76.6	6.1	7.1	13.2	10.1
16-50	-	4.4	16.4	18.5	16.6	6.8	62.7	2.4	5.9	8.3	29.1
50-75	-	3.7	11.5	17.1	18.4	8.5	59.2	5.5	5.6	11.1	29.8
75-130	-	4.7	11.8	16.5	17.1	7.6	57.7	4.8	6.4	11.2	31.0

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-16	-	35	-	-	10.1
30-40	1.712	-	-	-	-
16-50	-	100	-	-	29.1
70-80	1.484	-	-	-	-
50-75	-	102	-	-	29.8
75-130	-	111	-	-	31.0

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
30-40	1.712	37.3	37.3	35.5	32.4	30.9	29.4	25.9	23.4
70-80	1.484	42.9	41.9	38.1	32.2	29.5	27.4	26.3	22.4

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
0-16	6.7	5.3	0.07	0.7	0.55	-	-	-	-	2.2	2.3	0.4	0.0	4.9
16-50	7.1	5.8	0.53	1.3	0.56	-	-	-	-	3.9	7.3	0.9	1.5	13.6
50-75	8.2	6.9	1.73	1.7	0.24	-	-	-	-	4.4	8.1	0.9	4.0	17.4
75-130	8.5	7.3	2.41	2.0	0.11	-	-	-	-	4.2	8.1	0.9	5.6	18.8

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 %
0-16	84	5.8	57	1.9	-	-	0
16-50	96	14.2	49	2.0	-	-	11
50-75	107	16.2	54	0.8	-	-	25
75-130	111	17.0	55	0.4	-	-	33

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
0-16	-	-	-	0.04	0.02	0.41	0.05	0.03	0.01	-	0.11
16-50	-	-	-	0.10	0.03	0.68	0.13	0.05	0.04	-	0.09
50-75	-	-	-	0.07	0.04	0.52	0.08	0.01	0.01	-	0.05
75-130	-	-	-	0.05	0.04	0.49	0.06	0.00	0.01	-	0.03

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-16	-	very weak to weak	-	-	-	-	weak	weak	weak	weak to medium	weak	-
16-50	-	very weak to weak	-	-	-	-	weak to medium	weak	weak to medium	weak	weak	-
50-75	-	very weak to weak	-	-	-	-	weak to medium	weak	medium to strong	weak	weak	-
75-130	-	very weak to weak	-	-	-	-	weak to medium	weak	medium to strong	weak	weak	-

Profile description

AE 0-16 cm	dark greyish brown (10YR 4/2, dry) very dark brown (10YR 2/2, moist)sandy loam,moderately coherent and porous massive weak medium subangular blocky,slightly hard friable non sticky slightly plastic,common micro exped and inped interstitial pores and common exped and inped tubular pores,common micro and few very fine roots,slightly calcareous (0-2%),clear smooth boundary to,
Btn 16-50 cm	dark brown (10YR 3/3, dry) very dark greyish brown (2.5Y 3/2, moist)sandy clay loam,moderate very coarse columnar parting to moderate very coarse angular blocky,very hard very friable sticky plastic,few (2-5%) fine faint sharp mottles10YR5/6 (yellowish brown) and few (2-5%) fine distinct sharp mottles BLACK0/0 (Invalid Code:),broken thick clay and humus cutans,few micro inped interstitial pores and inped tubular pores,common micro roots,slightly calcareous (0-2%),clear smooth boundary to,
BCkc 50-75 cm	dark yellowish brown (10YR 4/4, dry) (dark) brown (10YR 4/3, moist)sandy clay loam,moderate coarse angular blocky,hard friable slightly sticky slightly plastic,patchy thin clay and humus cutans,common micro inped interstitial pores and few very fine interstitial pores,common micro roots,few small irregular hard calcareous concretions and few medium irregular hard calcareous concretions,slightly calcareous (0-2%),gradual smooth boundary to,
Ckc 75-130 cm	(10YR 4.5/4, dry) (dark) brown (10YR 4/3, moist)sandy clay loam,weak coarse angular blocky,hard friable sticky plastic,many micro exped and inped interstitial pores and common very fine interstitial pores,few micro roots,few small irregular hard calcareous concretions and few large irregular hard calcareous concretions,moderately calcareous (2-10%),

Kind 1 (parent material) ; Parker (eds), 1984	sediment, unconsolidated
Mode of accumulation or deposition of parent material	marine sediments
Texture of parent material	loamy
Weathering Resistance	moderate
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
Intensity of the soil erosion type (second entry)	harmless
Soil erosion type	sheet
Soil erosion type (second entry)	wind

Major crops	rice
Land use or vegetation in the immediate vicinity of the site	wet rice cultivation
Remarks on Land Use / Vegetation	VEGETATION: bushy
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	grassland

Altitude	30m
Physiographic Unit	near depression
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.	plain
Slope	0%
Slope Aspect	west
Form of the slope surrounding the site	straight
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	undulating

Lower limit of a slow permeable or stagnating layer in the profile	75cm
Drainage class ; FAO (2006) - Guidelines for soil description	poor
Dry From - To	0-130cm
(Estimated) maximum (lower) depth to groundwater table	0cm
Depth to groundwater table	0cm
Kind of ground water table (USDA, 1979)	no groundwater table observed
(Estimated) minimum (upper) depth to groundwater table	200cm
Estimated permeability (class) of least permeable part of the profile	slow
Estimated run off (class)	ponded
Upper limit of a slow permeable or stagnating layer in the profile	16cm

Evidence of alkali ; Soil Survey Manual USDA, 1951	slightly alkaline
Surface cracking	no cracks observed
Slaking of aggregates by tillage, rainfall or frost (USDA/SCS, 1979)	surface slaked; sorted sand/silt, some clay films
Microrelief Height: variation in height	50
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	termite/ant mounds
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 Mozambique 09: Solonetz

Characteristics

Reference soil MZ009: Solonetz

Classification