Reference soil Mozambique 07: Planosol

MZ007

Planosols occur in level landscapes throughout the world often associated with broad river valleys.

Characteristics

Soils having an eluvial horizon, the lower boundary of which is marked. within 100 cm from the soil surface, by an abrupt textural change associated with stagnic properties above that boundary. The feature of albeluvic tonguing, however, is lacking.

Distribution of Planosols (rough estimation supplied by soilgrids)

Reference soil MZ007: Planosols

CLASSIFICATION: USDA-subgroup : Thapto Haplustultic. FAO : coarse textured. PHYSIOGRAPHY: slope length: 300 m. pattern macro relief: uniform. irregular meso relief of remnants of termite mounds, 6-12/ha, 20-50 cm high, diameter 5.2 m. Besides small (20-40 cm high, diameter 20-30 cm) active termite mounds (15-40/ha); old ones with bush. Old >4%, new <2%. sealing: rather compacted. crusting:frequently with not very hard crust of 1-4 mm. AGGRADATION: Deposition of bleached quartz grains. VEGETATION: Coverage(%):regionallocal shrubs1-31 herbs30-4030 grasses40-5040 bare ground20-3030 SOIL FAUNA: Very high activity of all kinds of termites and ants. BRIEF CHARACTERIZATION OF THE SOIL: Normal A-horizon, overlying a deep E-horizon. E is mottled, especially in EB, structureless, well rooted, hard when dry. Abrupt transition to Bt, which's top is also bleached in the same fashion as the tongues reaching to the top of Bt2, thick dark cutans, with many orange mottles. Bt2 has even more pronounced cutans, without mottles. The calcaric C has lost the structure of the rock through rooting to great depth. In both Bt2 and C the rooting is also horizontal and tubular pores occur. ADDITIONAL NOTES ON PROFILE DESCRIPTION: A1 -pores: interstitial, vesiculair and tubular. -roots: also few medium roots. E -pores: also common fine-medium insterstitial, vesiculair and tubular pores. -roots: also few medium roots. EB -sometimes top prisma still visible. -roots: also few medium roots. -pores: also common fine-medium insterstitial, vesiculair and tubular pores. Bt1 -structure: also moderate coarse prismatic. -mottles: also few black fine distinct sharp mottles. -cutans: also in pores. -second pores: also vesiculair. -roots: also few medium. -tonguing of bleached sand rather clear. -top prisms bleached. Bt2 -pores: also common very fine-fine tubular and vesiculair. -roots: also few medium. C -inlusion type II: also ferrigenous.

Classification

WRB 2006

WRB 1998

Luvic- Planosol (Albic Sodic Epidystric)

Luvi-Hyposodic- Planosol (Albic Epidystric)

105-135 cm	natric horizon
15-58 cm	albic horizon
58-105 cm	argic horizon
-	reducing conditions
-	stagnic colour pattern
-	abrupt textural change

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Epidystri-Stagnic Solonetz

Solodic Planosol

0-15 cm	ochric A horizon
105-135 cm	natric B horizon
15-58 cm	albic E horizon
-	stagnic

0-15 cm	ochric A horizon
15-58 cm	albic E horizon
58-135 cm	natric B horizon
-	abrupt textural change
-	hydromorphic

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
0-15	-	4.5	21.2	27.8	23.0	6.9	83.4	4.7	5.5	10.2	6.4
15-38	-	4.1	19.6	29.2	25.3	6.7	84.9	4.5	3.9	8.4	6.8
38-58	-	4.1	19.8	28.1	22.3	5.9	80.2	4.7	4.2	8.9	10.8
58-105	-	5.1	18.2	23.0	17.2	4.3	67.8	3.1	3.7	6.8	25.4
105-135	-	5.3	14.9	21.3	16.0	4.9	62.4	2.9	8.0	10.9	26.7
135-	-	5.3	12.2	18.5	15.9	4.6	56.5	3.2	9.5	12.7	30.9

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
70-80	1.673	-	-	-	-
0-15	-	21	-	-	6.4
110-120	1.609	-	-	-	-
15-38	-	18	-	-	6.8
38-58	-	36	-	-	10.8
58-105	-	90	-	-	25.4
105-135	-	102	-	-	26.7
135-	-	118	-	-	30.9

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
70-80	1.673	32.8	31.4	28.0	23.5	21.3	19.8	22.1	19.9
110-120	1.609	41.2	40.5	37.3	32.9	30.8	28.8	26.9	23.9

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
0-15	5.7	4.8	0.06	-	0.42	0.04	11	-	-	0.2	0.8	0.3	0.0	1.3
15-38	6.0	4.9	0.04	1.0	0.24	-	-	-	-	0.2	0.8	0.2	0.0	1.2
38-58	5.9	4.6	0.07	1.0	0.20	-	-	-	-	0.2	1.6	0.3	0.0	2.1
58-105	6.2	4.9	0.20	1.4	0.19	-	-	-	-	2.3	4.8	0.7	0.5	8.3
105-135	7.7	6.0	0.52	1.7	0.16	-	-	-	-	3.6	6.3	1.0	2.8	13.7
135-	8.4	6.8	1.10	2.1	0.10	-	-	-	-	4.4	7.2	1.2	4.1	16.9

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 %
0-15	33	3.9	61	1.5	-	-	0
15-38	39	3.1	46	0.8	-	-	0
38-58	43	4.9	45	0.7	-	-	0
58-105	66	12.6	50	0.7	-	-	4
105-135	84	16.4	61	0.6	-	-	17
135-	92	18.4	60	0.4	-	-	22

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
0-15	-	-	-	0.02	0.01	0.25	0.03	0.02	0.01	-	0.06
15-38	-	-	-	0.02	0.01	0.24	0.03	0.03	0.01	-	0.05
38-58	-	-	-	0.04	0.02	0.34	0.05	0.05	0.05	-	0.07
58-105	-	-	-	0.07	0.03	0.51	0.08	0.01	0.01	-	0.07
105-135	-	-	-	0.05	0.04	0.46	0.07	0.01	0.02	-	0.04
135-	-	-	-	0.05	0.05	0.51	0.11	0.00	0.00	-	0.03

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-15	-	very weak to weak	-	-	-	-	weak to medium	weak to medium	weak	weak to medium	weak to medium	-
15-38	-	very weak to weak	-	-	-	-	weak to medium	weak to medium	weak	weak to medium	weak to medium	-
38-58	-	very weak to weak	-	-	-	-	weak to medium	weak to medium	weak	medium to strong	weak to medium	-
58-105	-	very weak to weak	-	-	-	-	weak to medium	weak to medium	weak	weak	medium to strong	-
105-135	-	very weak to weak	-	-	-	-	weak to medium	weak to medium	weak	weak to medium	strong	-
135-	-	very weak to weak	-	-	-	-	weak to medium	weak	weak	weak to medium	strong	-

Profile description

Ah 0-15 cm	dark greyish brown (10YR 4/2, dry) very dark greyish brown (10YR 3/2, moist)loamy sand,moderately coherent porous massive and weak medium and coarse subangular blocky,slightly hard very friable non sticky non plastic,common very fine and fine discontinuous inped pores and few medium discontinuous inped pores,many fine and common medium roots,coarse quartz grains,non calcareous,clear smooth boundary to,
E 15-38 cm	(10YR 5.5/2, dry) (10YR 4/2.5, moist)loamy sand,moderately coherent porous massive,slightly hard very friable non sticky non plastic,common (5-15%) fine faint diffuse mottles 10YR4/4 (dark yellowish brown),many micro to coarse discontinuous inped interstitial pores and few very fine discontinuous inped vesicular pores,many fine and common medium roots,coarse quartz grains,slightly calcareous (0-2%),clear smooth boundary to,
EB 38-58 cm	brown (10YR 5/3, dry) (dark) brown (10YR 4/3, moist)loamy sand,moderately coherent porous massive,hard very friable non sticky non plastic,many (15-40%) fine faint clear 10YR4/4 mottles and (dark yellowish brown) many (15-40%) medium distinct diffuse 10YR4/6 (dark yellowish brown) mottle,many micro to coarse discontinuous inped interstitial pores and few very fine discontinuous inped vesicular pores,many fine and common medium roots,slightly calcareous (0-2%),abrupt smooth boundary to,
Bt 58-105 cm	greyish brown (2.5Y 5/2, dry) dark greyish brown (2.5Y 4/2, moist)sandy clay loam,moderate coarse and very coarse prismatic parting to moderate very coarse angular blocky,extremely hard friable sticky slightly plastic,many (15-40%) medium distinct clear mottles and 7.5YR5/6 (strong brown) many (15-40%) coarse prominent clear 7.5Y5/8 (Invalid Code:) mottles,continuous thick clay and humus cutans on horizontal and vertical pedfaces,common micro and very fine discontinuous inped interstitial pores and few very fine and fine discontinuous inped tubular pores,common fine and few medium and coarse roots,slightly calcareous (0-2%),clear smooth boundary to,
Btn 105-135 cm	greyish brown (2.5Y 5/2, dry) dark greyish brown (2.5Y 4/2, moist)sandy clay loam,moderate coarse angular blocky,very hard friable sticky slightly plastic,patchy moderately thick clay and humus cutans,many micro to fine continuous inped interstitial pores and few very fine to medium discontinuous inped tubular pores,common fine and few medium and coarse roots,slightly calcareous (0-2%),clear smooth boundary to,
Cn 135-135 cm	(2.5Y 5/3, dry) (2.5Y 4/3, moist)sandy clay loam,moderate very coarse angular blocky,hard friable sticky slightly plastic,many micro to fine discontinuous inped interstitial pores and few very fine discontinuous inped vesicular pores,few fine and medium roots,very few medium irregular hard calcareous concretions and very few small spherical hard manganiferous 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	sandy clay
Weathering Resistance	moderate
General characterization of the status of weathering of solid rock	partially or moderately

Occurrence of soil aggradation (McDonald et al., 1984)	present
Intensity of the soil erosion type	slight
Soil erosion type	sheet

Land use or vegetation in the immediate vicinity of the site	semi-natural grassland, grazed
Remarks on Land Use / Vegetation	VEGETATION: shrubs mainly on termite mounds
Major vegetation type; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	grassland

Physiographic Unit	slope
Physiographic position of the site	crest
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	concave
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	undulating

Drainage class ; FAO (2006) - Guidelines for soil description	imperfect
Flooding frequency (FAO, 1986)	never
Kind of ground water table (USDA, 1979)	no groundwater table observed
Estimated permeability (class) of least permeable part of the profile	slow
Estimated run off (class)	slow

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	30
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 07: Planosol

Characteristics

Reference soil MZ007: Planosols

Classification