Reference soil Nigeria 23: Acrisol

NG023

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 NG023: Acrisols

Acrisol

Classification

WRB 2006

WRB 1998

Haplic- Acrisol (Alumic Hyperdystric Profondic Clayic)

Alumi-Profondic- Acrisol (Hyperdystric Chromic)

20-175 cm

argic horizon

FAO-UNESCO-ISRIC 1988

FAO-UNESCO-ISRIC 1974

Chromi-Haplic Acrisol

Ferric Acrisol

0-20 cm	ochric A horizon
20-175 cm	argic B horizon

0-20 cm	ochric A horizon
20-175 cm	argillic B horizon
-	ferric

Local classification:	Erinoke Series

Other classification

USDA-SCS (1975)

Haplustult ustic sandy over loamy kaolinitic isohyperthermic

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
0-20	40	24.7	18.3	13.5	10.9	3.8	71.2	3.9	6.6	10.5	18.3
20-42	40	22.6	16.3	9.6	7.6	3.2	59.3	3.7	6.2	9.9	30.8
42-60	36	18.6	13.6	7.4	6.0	2.6	48.2	1.0	6.4	7.4	43.3
60-98	19	14.6	11.3	8.2	7.4	3.5	45	2.3	8.8	11.1	43.9
98-136	0	8.0	7.2	6.4	7.0	4.0	32.6	3.9	11.8	15.7	51.7
136-175	0	8.0	8.3	8.0	8.5	4.4	37.2	4.9	11.1	16	46.9
175-256	0	12.1	10.0	8.6	8.7	4.4	43.8	4.8	13.4	18.2	38.1
256-297	0	8.4	10.2	9.8	10.8	4.9	44.1	4.9	14.9	19.8	36.1
297-343	0	4.2	11.1	17.7	20.7	10.0	63.7	8.4	18.0	26.4	9.9
343-395	0	3.0	11.7	18.1	21.8	10.4	65	9.0	18.5	27.5	7.6
395-433	0	3.7	12.4	18.6	21.2	10.8	66.7	8.1	18.8	26.9	6.4

Water retention characteristics

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-20	-	-	-	11.5	18.3
20-42	-	-	-	25.3	30.8
42-60	-	-	-	32.9	43.3
60-98	-	-	-	1.5	43.9
98-136	-	-	-	1.0	51.7
136-175	-	-	-	1.0	46.9
175-256	-	-	-	1.0	38.1
256-297	-	-	-	0.4	36.1
297-343	-	-	-	0.0	9.9
343-395	-	-	-	0.0	7.6
395-433	-	-	-	0.0	6.4

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
0-20	5.7	4.6	0.04	-	1.21	0.11	11	0.4	0.2	1.8	1.0	0.1	0.0	2.9
20-42	5.0	4.1	0.02	-	0.70	0.06	12	2.1	1.6	0.6	0.3	0.1	0.0	1
42-60	4.9	4.1	0.02	-	0.56	0.05	11	2.3	2.3	0.4	0.3	0.0	0.0	0.7
60-98	4.9	4.1	0.01	-	0.37	0.04	9	2.5	2.5	0.4	0.0	0.0	0.3	0.7
98-136	5.0	4.1	0.01	-	0.26	0.03	9	2.8	2.7	0.4	0.0	0.0	0.0	0.4
136-175	5.2	4.1	0.01	-	0.25	0.03	8	2.3	1.8	0.2	0.0	0.0	0.1	0.3
175-256	5.2	4.2	0.01	-	0.12	0.02	6	1.7	1.1	0.2	0.3	0.0	0.0	0.5
256-297	5.1	4.1	0.01	-	0.11	0.01	11	1.7	1.1	0.0	0.0	0.0	0.2	0.2
297-343	5.4	4.2	0.01	-	0.03	0.00	-	1.2	0.7	0.0	0.0	0.0	0.0	-
343-395	5.4	4.3	0.01	-	0.17	0.01	17	1.2	1.1	0.2	0.0	0.0	0.0	0.2
395-433	5.1	4.3	0.01	-	0.03	-	-	1.2	0.9	0.0	0.0	0.0	0.0	-

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 %
0-20	59	4.9	27	4.2	-	4	0
20-42	20	4.9	16	2.5	-	33	0
42-60	15	4.8	25	2.0	-	48	0
60-98	13	5.2	12	1.3	-	48	6
98-136	7	5.6	11	0.9	-	48	0
136-175	7	4.5	10	0.9	-	40	2
175-256	11	4.4	12	0.4	-	25	0
256-297	5	4.2	12	0.4	-	26	5
297-343	-	2.6	26	0.1	-	27	0
343-395	8	2.6	34	0.6	-	42	0
395-433	-	2.6	41	0.1	-	35	0

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
0-20	-	-	-	0.08	0.00	1.59	0.24	-	-	-	0.10
20-42	-	-	-	0.13	0.00	2.71	0.42	-	-	-	0.13
42-60	-	-	-	0.12	0.00	3.62	0.59	-	-	-	0.12
60-98	-	-	-	0.12	0.00	4.24	0.56	-	-	-	0.12
98-136	-	-	-	0.15	0.03	4.74	0.43	-	-	-	0.13
136-175	-	-	-	0.15	0.03	4.42	0.44	-	-	-	0.13
175-256	-	-	-	0.10	0.02	4.18	0.34	-	-	-	0.10
256-297	-	-	-	0.10	0.02	4.10	0.30	-	-	-	0.07
297-343	-	-	-	0.05	0.02	4.70	0.15	-	-	-	0.05
343-395	-	-	-	0.05	0.00	5.18	0.12	-	-	-	0.05
395-433	-	-	-	0.05	0.00	5.28	0.15	-	-	-	0.05

Clay mineralogy

Depth (cm)	Chlorite	Feldspar	Gibbsite	Goethite	Halloysite	Hematite	Kaolinite	Mica / illite	Mixed-layer	Quartz	Smec	Vermiculite
0-20	-	-	very weak to weak	weak	-	-	very strong	weak	weak	very weak to weak	-	-
20-42	-	-	very weak to weak	weak to medium	-	-	very strong	weak	weak	very weak	-	-
42-60	-	-	very weak to weak	weak to medium	-	-	very strong	very weak	weak	very weak	-	-
60-98	-	-	very weak to weak	weak to medium	-	-	very strong	very weak	weak	-	-	-
98-136	-	-	very weak to weak	weak to medium	-	-	very strong	very weak	very weak	-	-	-
136-175	-	-	very weak to weak	weak to medium	-	-	very strong	very weak	very weak to weak	-	-	-
175-256	-	-	very weak to weak	weak to medium	-	-	very strong	-	very weak to weak	-	-	-
256-297	-	-	very weak	weak to medium	-	-	very strong	-	very weak to weak	-	-	-
297-343	-	-	-	weak to medium	-	-	very strong	-	very weak	-	-	-
343-395	-	-	-	weak to medium	-	-	very strong	-	-	-	-	-
395-433	-	-	-	weak to medium	-	-	very strong	-	-	-	-	-

Profile description

Ah 0-20 cm	very dark greyish brown (10YR 3/2, dry)very gravelly sandy loam,weak medium crumb,friable non plastic,many fine discontinuous exped and inped tubular random pores,many very fine and fine roots,common medium gravel weathered quartz fragments,non calcareous,diffuse wavy boundary to,
BA 20-42 cm	(2.5YR 4/3, dry)very gravelly sandy loam,weak medium subangular blocky,slightly hard friable non plastic,many fine discontinuous exped and inped tubular oblique pores,many fine and medium roots,common medium gravel weathered quartz fragments,non calcareous,diffuse wavy boundary to,
Bt1 42-60 cm	reddish brown (2.5YR 4/4, dry)gravelly sandy loam,moderate medium crumb,slightly hard firm slightly sticky,many fine continuous inped tubular vertical pores,many fine roots,common medium gravel weathered quartz fragments,non calcareous,clear smooth boundary to,
Bt2 60-98 cm	red (2.5YR 4/6, dry)gravelly sandy clay loam,moderate medium subangular blocky,slightly hard firm slightly sticky,many fine discontinuous exped interstitial vertical pores,few very fine roots,few fine gravel weathered quartz fragments,non calcareous,gradual wavy boundary to,
Bt3 98-136 cm	red (2.5YR 4/6, dry)sandy clay loam,moderate medium subangular blocky,slightly hard firm slightly sticky,many (15-40%) medium distinct diffuse mottles 2.5Y8/2 (white),few fine discontinuous inped interstitial vertical pores,few fine gravel weathered mica fragments,non calcareous,clear smooth boundary to,
136-175 cm	dark red (2.5YR 3/6, dry)sandy clay loam,moderate medium subangular blocky,slightly hard firm slightly sticky,many (15-40%) medium distinct clear mottles 2.5Y8/2 (white),few very fine continuous inped interstitial oblique pores,few fine gravel fresh mica fragments,non calcareous,

Kind 1 (parent material) ; Parker (eds), 1984	acidic schist
Kind 2 (parent material) (second entry); Parker (eds), 1984	quartzite
Mode of accumulation or deposition of parent material	colluvial
Mode of accumulation or deposition of parent material (second entry)	residual material
Soil Depth	136cm
Texture of parent material	loamy
Texture of parent material (second entry)	gravelly
Weathering Resistance	high
Weathering Resistance (second entry)	high
General characterization of the status of weathering of solid rock	partially or moderately
General characterization of the status of weathering of solid rock (second entry)	partially or moderately

Intensity of the soil erosion type	slight
Slope stability	stable

Land use or vegetation in the immediate vicinity of the site	fallow
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)	semi-deciduous forest

Altitude	0m
Physiographic position of the site	middle slope
Regional landform; McDonald, R.C., Isbell, R.F. et all, 1984; Australian soil and land survey Field Handbook, Inkata Press, Melbourne.	low hill
Slope	14%
Form of the slope surrounding the site	straight
Topography; Guidelines for soil description - Fourth edition (FAO, Rome, 2006)	rolling

Drainage class ; FAO (2006) - Guidelines for soil description	well
Dry From - To	0-175cm
Kind of ground water table (USDA, 1979)	no groundwater table observed

Evidence of alkali ; Soil Survey Manual USDA, 1951	non-alkaline
Average size of stone	0.3
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)	none
Evidence of salt; Soil Survey Manual USDA, 1951	non-saline
Shape of stones (on average)	angular irregular
Surface stoniness class (FAO (2006) - Guidelines for soil description)	stony

You are here

Reference soil Nigeria 23: Acrisol

Characteristics

Reference soil NG023: Acrisols

Classification