Reference soil Mozambique 06: Acrisol

MZ006

Acrisols occur dominantly in the wetter parts of the tropics and subtropics and the warm temperate regions in relatively young landscapes.

Characteristics

Soils having an argic horizon (a subsurface horizon with distinct higher clay content than the overlying horizon), which has a cation exchange capacity of less than 24 cmolc per kg in some part, either starting within 100 cm from the soil surface, or within 200 cm from the soil surface if the argic horizon is overlain by loamy sand or coarser textures throughout. They have a base saturation (total amount of Ca, Mg, K and Na with respect to the cation exchange capacity) of less than 50 percent in the major part between 25 and 100 cm from the soil surface

Distribution of Acrisols (rough estimation supplied by soilgrids)

Reference soil MZ006: Acrisols

A deep, well drained, yellowish red sandy clay (loam) with a loamy sand topsoil and having a strongly mottled low permeable subsoil deeper than 150 cm. Texture is sandy clay from 93 to 121 cm. Medium to large size, dome and chimney shaped, termite mounds. The structure of the topsoil can also be described as single grain or massive porous/weakly coherent. In the topsoil are holes filled with redder coloured subsoil; in the subsoil are holes filled with darker coloured topsoil. At 90 cm depth one can observe a slight increase in clay content. Termite holes are present, density about 2 per square meter. The strong mottling in the subsoil is caused by temporarily stagnant water.

Classification

WRB 2006

WRB 1998

Cutanic- Acrisol (Profondic Clayic Chromic)

Chromi-Profondic- Acrisol

52-160 cm

argic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Chromi-Haplic Acrisol

Ferric Acrisol

0-21 cm	ochric A horizon
52-160 cm	argic B horizon

0-21 cm	ochric A horizon
52-160 cm	argillic B horizon
-	ferric

Other classification

USDA-SCS (1975)

Paleustalf ustic sandy over loamy kaolinitic hyperthermic

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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
0-21	-	4.7	16.7	27.6	23.9	6.7	79.6	3.7	4.3	8	12.3
21-52	-	5.4	19.0	30.2	22.9	5.3	82.8	2.4	2.6	5	12.2
52-93	-	7.0	21.0	24.7	16.3	4.2	73.2	2.2	1.5	3.7	23.1
93-121	-	11.2	15.3	13.2	8.8	3.0	51.5	1.9	1.9	3.8	44.6
131-160	-	4.6	8.8	9.2	7.7	3.4	33.7	3.3	4.1	7.4	58.9
275-310	-	12.8	15.2	11.7	8.9	4.5	53.1	7.0	9.0	16	30.8
325-375	-	12.8	12.4	7.7	4.9	2.6	40.4	5.3	8.3	13.6	46.0

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-21	1.425	17	-	10.2	12.3
21-52	-	13	-	12.4	12.2
52-93	1.612	23	-	3.4	23.1
93-121	-	44	-	10.8	44.6
131-160	1.601	62	-	2.3	58.9
275-310	-	54	-	2.5	30.8
325-375	-	56	-	2.0	46.0

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
0-21	1.425	39.0	33.4	21.4	15.7	14.3	13.0	16.3	14.7
52-93	1.612	34.8	33.0	27.6	22.9	21.7	20.3	26.7	25.6
131-160	1.601	38.5	37.9	36.1	34.1	33.3	32.1	26.7	25.7

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
0-21	6.3	5.7	0.05	-	1.03	0.06	17	0.0	0.0	2.2	0.4	0.0	0.1	2.7
21-52	6.2	4.8	0.04	-	0.22	-	-	0.0	0.1	0.8	0.2	0.2	0.0	1.2
52-93	6.0	4.7	0.04	-	0.49	0.03	16	0.0	0.1	1.2	0.2	0.0	0.1	1.5
93-121	5.9	5.1	0.04	-	0.45	-	-	0.0	0.1	1.8	0.3	0.0	0.1	2.2
131-160	6.2	5.6	0.03	-	0.27	-	-	0.0	0.0	3.1	0.5	0.0	0.1	3.7
275-310	5.5	5.4	0.03	-	0.22	-	-	0.1	0.0	0.2	0.8	0.0	0.1	1.1
325-375	5.4	4.7	0.04	-	0.25	-	-	0.2	0.2	0.3	1.1	0.0	0.1	1.5

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 %
0-21	50	5.4	44	3.6	-	0	2
21-52	48	2.5	20	0.8	-	4	0
52-93	38	4.0	17	1.7	-	3	3
93-121	51	4.3	10	1.6	-	2	2
131-160	67	5.5	9	0.9	-	0	2
275-310	19	5.9	19	0.8	-	0	2
325-375	29	5.2	11	0.9	-	4	2

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
0-21	-	-	-	0.10	0.02	0.41	0.07	0.03	0.12	-	0.04
21-52	-	-	-	0.05	0.00	0.37	0.06	0.04	0.11	-	0.02
52-93	-	-	-	0.06	0.00	0.61	0.08	0.04	0.03	-	0.02
93-121	-	-	-	0.09	0.00	1.07	0.12	0.02	0.02	-	0.02
131-160	-	-	-	0.10	0.03	1.74	0.18	0.00	0.02	-	0.03
275-310	-	-	-	0.08	0.02	6.44	0.41	0.00	0.03	-	0.07
325-375	-	-	-	0.09	0.02	3.21	0.24	0.00	0.03	-	0.06

Elemental composition of the soil

Depth (cm)	Al2O3 % w/w	CaO % w/w	Fe2O3 % w/w	K2O % w/w	MgO % w/w	Na2O % w/w	SiO2 % w/w	TiO2 % w/w
0-21	5.4	0.07	1.4	0.37	0.06	-	90.1	0.82
21-52	5.1	0.01	1.3	0.29	0.04	-	92.5	0.75
52-93	8.8	0.01	1.7	0.23	0.50	-	86.9	0.73
93-121	15.8	0.02	2.6	0.20	0.03	0	75.3	0.85
131-160	22.9	0.05	4.1	0.18	0.04	0	64.3	1.06
275-310	17.9	0.00	16	0.02	0.04	-	58.5	0.99
325-375	20.4	0	8	0.05	0.05	-	64.6	0.96

Depth (cm)	Al2O3/Fe2O3 mol/mol	LOI % w/w	MnO2 % w/w	P2O5 % w/w	SiO2 / Al2O3 mol/mol	SiO2/Fe2O3 mol/mol	SiO2 / R mol/mol
0-21	6	3.1	0.05	0.03	28.3	171	24.3
21-52	6.1	2.1	0.05	0.02	30.8	189.1	26.5
52-93	8.1	3.4	0.03	0.02	16.8	135.9	14.9
93-121	9.5	6.1	0.02	0.02	8.1	77	7.3
131-160	8.7	8.2	0.02	0.03	4.8	41.7	4.3
275-310	1.8	7.8	0.06	0.07	5.5	9.7	3.5
325-375	4.0	7.7	0.02	0.03	5.4	21.5	4.3

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-21	-	very weak to weak	-	weak	-	-	very strong	very weak to weak	-	very weak to weak	-	-
21-52	-	very weak	-	weak	-	-	very strong	very weak to weak	-	very weak to weak	-	-
52-93	-	very weak	-	weak	-	-	very strong	very weak	-	very weak to weak	-	-
93-121	-	very weak	-	weak	-	-	very strong	-	-	very weak to weak	-	-
131-160	-	-	-	weak	-	-	very strong	-	-	very weak	-	-
275-310	-	-	-	weak to medium	-	-	very strong	-	-	very weak	-	-
325-375	-	-	-	weak to medium	-	-	very strong	-	-	very weak	-	-

Sand mineralogy

Depth (cm)	Heavy Frac. sand % w/w	K-Feldspar % w/w	Light Fra. sand % w/w	Opaque % w/w	Plagioclase % w/w	Quartz % w/w
21-52	-	-	-	82	-	100
131-160	-	-	-	86	-	100
325-375	-	-	-	82	-	100

Minerals

Depth (cm)	Anatase % w/w	Andalusite % w/w	Apatite % w/w	Augite % w/w	Biotite % w/w	Hornblende (basaltic) % w/w
21-52	-	-	-	-	-	1
325-375	1	-	-	-	-	-

Depth (cm)	Brookite % w/w	Chloritic % w/w	Disthene % w/w	Epidote % w/w	Garnet % w/w	Glaucophane % w/w
131-160	-	-	-	1	-	-

Depth (cm)	Grenate % w/w	Grossular % w/w	Muscovite % w/w	Rutile % w/w	Sillimanite % w/w	Spinel % w/w
21-52	-	-	-	7	2	-
131-160	-	-	-	7	1	-
325-375	-	-	-	8	-	-

Profile description

Ah 0-21 cm	very dark grey (10YR 3/1, moist)loamy sand,weak fine and medium subangular blocky,loose non sticky non plastic,many very fine pores,many very fine roots,no inclusions,no fragments,termite channels,non calcareous,clear smooth boundary to,
E 21-52 cm	(7.5YR 3.5/2, moist)loamy sand,weak medium subangular blocky,loose non sticky non plastic,many fine pores,many very fine roots,termite channels,non calcareous,clear smooth boundary to,
Bt 52-121 cm	yellowish red (5YR 4/6, moist)sandy clay loam,weakly coherent porous massive,very friable slightly sticky slightly plastic,patchy thin clay cutans,many very fine and fine pores,common very fine and fine roots,termite channels,non calcareous,gradual smooth boundary to,
Btg 121-165 cm	red (2.5YR 4/6, moist)sandy clay,weak medium angular blocky,very hard friable sticky slightly plastic,many (15-40%) prominent mottles 10YR7/1 (light grey) and many (15-40%) prominent mottles 10YR6/6 (brownish yellow),many very fine and fine pores,few very fine and fine roots,termite channels,non calcareous,

Kind 1 (parent material) ; Parker (eds), 1984	granite
Mode of accumulation or deposition of parent material	residual material
Remarks on Parent Materials	Basement Complex
Soil Depth	165cm
Texture of parent material	sandy clay
General characterization of the status of weathering of solid rock	highly

Major crops	cassava
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	low level arable farming
Remarks on Land Use / Vegetation	VEGETATION: Cashew; fallow grasses and herbs
Rotation scheme ; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	shifting - fallow grass
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)	grassland

Altitude	450m
Physiographic Unit	irregular interfluves
Physiographic position of the site	upper slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	peneplain
Slope	0%
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	0cm
Drainage class ; FAO (2006) - Guidelines for soil description	moderately well
Flooding frequency (FAO, 1986)	never
(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	121cm
Moist From - To	0-165cm
Estimated permeability (class) of least permeable part of the profile	moderate
Estimated run off (class)	very slow
Drainage class - intergrade; FAO (2006) - Guidelines for soil description	well
Upper limit of a slow permeable or stagnating layer in the profile	165cm

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
Micro relief type: small-scale differences in relief in the direct vicinity of the site (FAO, 1986)	termite/ant mounds
Microrelief pattern	isolated
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 06: Acrisol

Characteristics

Reference soil MZ006: Acrisols

Classification