Reference soil Samoa 01: Ferralsol

WS001

Distribution of Ferralsols (rough estimation supplied by soilgrids)

FAO-UNESCO-ISRIC 1974

Orthic Ferralsol

Local classification

Classification information

Vaipouli series

Other classification

USDA-SCS (1975)

Haplorthox perudic loamy gibbsitic isohyperthermic

Location:

Lavai'i Island, Avao-uta banana trial, near Vaipouli College

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
0-12	32.0	0.03	33.3	0.01	0.78	-	0	7.68
12-18	34.3	0	35.8	0	0.74	-	0	8.06
18-28	34.3	0	35.9	0	0.73	-	0	8.11
28-50	34.3	0	35	0.01	0.71	-	0	8.38
50-80	34.7	0	35.6	0.01	0.49	-	0	7.66
80-100	34.5	0	35.9	0.01	0.56	-	0.1	7.7
100-120	34.6	0	36	0.01	0.65	-	0.2	7.73
120-138	34.5	0	35	0.01	0.64	-	0	7.97
138-150	33.6	0.01	34.8	0.01	0.78	-	0.1	8.61

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
0-12	-	26.4	0.62	0.67	-	-	-
12-18	-	21.6	0.45	0.75	-	-	-
18-28	-	21.3	0.47	0.77	-	-	-
28-50	-	21.1	0.45	0.84	-	-	-
50-80	-	21.8	0.26	0.82	-	-	-
80-100	1.5	21.4	0.41	0.80	0	0	0
100-120	1.5	21.2	0.23	0.65	0	0	0
120-138	-	21.3	0.44	0.87	-	-	-
138-150	1.5	23.3	0.55	0.70	0	0	0

Physical

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
0-12	-	0.6	2.1	1.3	0.5	0.3	4.8	7.2	45.5	52.7	42.5
12-18	-	0.3	0.9	0.8	0.4	0.3	2.7	23.6	51.4	75	22.4
18-28	-	0.4	1.1	0.8	0.4	0.3	3	17.6	54.6	72.2	24.7
28-50	-	0	0.3	0.4	0.3	0.1	1.1	10.2	56.9	67.1	31.7
50-80	-	1.7	2.2	1.4	1.1	0.6	7	19.3	45.6	64.9	28.1
80-100	-	1.3	1.9	1.8	1.6	0.8	7.4	23.3	46.1	69.4	23.1
100-120	-	1.2	2.9	2.9	3.3	2.3	12.6	24	48.4	72.4	15
120-138	-	0	0.6	0.7	0.6	0.5	2.4	20.4	49.4	69.8	27.8
138-150	-	0.4	1.3	1.3	0.5	0.3	3.8	13.4	50.9	64.3	32

Other physical data

Depth (cm)	Bulk density kg/dm³	Spec. Surf. Area m²/g	COLE cm/cm	Water disp. clay %	Clay % w/w
0-12	-	-	-	16.5	42.5
12-18	-	-	-	26	22.4
18-28	-	-	-	27	24.7
28-50	-	-	-	27.8	31.7
50-80	-	-	-	26.8	28.1
80-100	-	-	-	21.5	23.1
100-120	-	-	-	16.7	15
120-138	-	-	-	32.6	27.8
138-150	-	-	-	1.5	32

Chemical characteristics:

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
0-12	4.0	4.6	0.67	-	4.74	0.53	9	0.4	0.1	0.2	0.2	0	0.0	0.4
12-18	4.0	5.8	0.24	-	0.63	0.51	1	0	0	0.0	0.0	0	0.0	0
18-28	3.9	5.9	0.21	-	0.41	0.45	1	0	0	0.2	0.1	0	0.0	0.3
28-50	3.8	6.1	0.24	-	0.24	0.33	1	0	0	0.0	0.0	0	0.0	0
50-80	4.2	6.1	0.15	-	0.38	0.29	1	0	0	0.0	0.0	0	0.0	0
80-100	4.1	6.0	0.14	-	0.22	0.26	1	0	0	0.2	0.0	0	0.0	0.2
100-120	3.7	5.9	0.21	-	0.18	0.23	1	0	0	0.4	0.0	0	0.2	0.6
120-138	4.2	6.1	0.18	-	0.22	0.03	7	0	0	0.2	0.0	0	0.0	0.2
138-150	3.7	5.0	0.3	-	2.27	0.15	15	0.1	0.1	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 %
0-12	2	21.4	50	16.6	-	0	-
12-18	0	8.4	38	2.2	-	0	-
18-28	4	7.9	32	1.4	-	0	-
28-50	0	8.3	26	0.8	-	0	-
50-80	0	8.3	30	1.3	-	0	-
80-100	3	7.8	34	0.8	-	0	-
100-120	9	6.7	45	0.6	-	0	-
120-138	2	8.4	30	0.8	-	0	-
138-150	0	13.8	43	7.9	-	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
0-12	8.6	-	-	0.68	0.1	10.4	3.34	2.57	1.05	-	0.42
12-18	8.9	-	-	0.3	0.1	12.1	3.09	0.44	1.16	-	0.48
18-28	8.7	-	-	0.3	0.1	12.36	3.15	0.34	0.14	-	0.5
28-50	8.7	-	-	0.32	0.1	11.59	3.15	0.31	0.13	-	0.77
50-80	8.9	-	-	0.32	0.1	14.18	3.7	0.41	0.18	-	0.79
80-100	9	-	-	0.34	0.1	13.92	3.59	0.26	0.12	-	1.02
100-120	9	-	-	0.31	0.1	12.24	3.12	0.19	0.09	-	1.05
120-138	8.9	-	-	0.3	0.1	12.24	3.2	0.29	0.12	-	0.78
138-150	8.9	-	-	0.41	0.1	11.59	3.36	1.78	0.59	-	0.42

Profile description

Ah1 0-12 cm	dark yellowish brown (10YR 4/4, moist)sandy clay loam,strong very fine and fine granular,firm,gradual smooth boundary to,
Ah2 12-20 cm	dark brown (10YR 3/3, moist)sandy loam,weak very fine and fine granular,firm,clear smooth boundary to,
20-30 cm	very dark grey (10YR 3/1, moist)clay loam,very fine granular,friable,gradual smooth boundary to,
Bo1 30-50 cm	dark greyish brown (10YR 4/2, moist)clay loam,weak fine granular,friable,clear smooth boundary to,
Bo2 50-82 cm	very dark greyish brown (10YR 3/2, moist)clay loam,weak subangular blocky,friable,gradual wavy boundary to,
Bo3 82-105 cm	(7.5YR 3.5/2, moist)clay loam,weak very fine and fine subangular blocky to granular,friable,few fine pores,few small hard manganiferous,gradual smooth boundary to,
Bs4 105-138 cm	(10YR 4/3.5, moist)clay loam,friable,clear smooth boundary to,
Bo6 150-180 cm	(dark) brown (10YR 4/3, moist)(dark) brown (10YR 4/3, moist),clay loam,clay loam,friable,friable,