Applied and Environmental Soil Science

Research Article

Soil Organic Carbon Distribution in a Humid Tropical Plain of Cameroon: Interrelationships with Soil Properties

Table 3

Morphological characteristics of the soils.


Horizon	Depth (cm)	Color		Structure	Consistence			Voids	Roots and biological features	Nodules/concretions	Boundary characteristics
Horizon	Depth (cm)	Moist	Dry	Structure	Dry	Moist	Wet	Voids	Roots and biological features	Nodules/concretions	Boundary characteristics

Profile 1. Bamia series
Ap	0–10	10YR 3/3	5YR 5/2	GR	SHA	FRF	VST and VPL	Few F and M	Common F, M, C, E, and T	VF quartz grains	C and S
AB	10–24	10YR 4/6	7.5YR 6/6	SB	HA	FRF	VST and VPL	Few F and M	Few F and M, E, and T	VF quartz grains	D and S
Bw₁	24–42	10YR 5/6	7.5YR 6/4	SB	HA	FI	VST and VPL	Few M	Few M and C, T	F quartz grains	D and S
Bw₂	42–72/90	2.5YR 5/2 (Matrix) 5Y 8/3 (inclusions) 10YR 6/8 (Inclusions) 10YR 6/4 (inclusions)	10YR 7/3 (Matrix) 10YR 7/6 (inclusions) 10YR 7/2 (inclusions)	SB	HA	FI	ST and PL	Few C	Very few C, T	M quarts grains	D and W
Bw₃	72/90–102	10YR 6/8	7.5YR 7/2	SB ⟶ GR, BL in places	HA	FI	SST and SPL	Few C	Very few C	M quarts grains	D and W
Cr₁	102–157	10YR 6/8	10YR 8/3	SB ⟶ GR	VHA	WE ⟶ FR	NST and NPL	Very few C	Very few M	Common	D and S
Cr₂	157–215	10YR 6/8	10YR 8/3	SB ⟶ GR	VHA	WE ⟶ FR	NST and NPL	Very few C	Very few F	Common	D and S

Profile 2. Santchou series
Ah	0–12	7.5YR 2/1	10YR 2/3	GR	HA	FR	SST and NPL	Many F and M	Common F, M, C, E and T	N	A
2Bt/E	12–38	7.5YR 6/1 (E) 7.5YR 5/6 (Bt)	10YR 6/3 (E) 10YR 7/6 (Bt)	BL	VHA	FI	VST and VPL	Few C	Very few C, T	VF quartz grains	C and S
2E/Bt	38–58	7.5YR 5/6 (matrix) 7.5YR 6/1 (mottles)	10YR 7/3 (matrix) 10YR 3/2 (mottles)	BL	VHA	FI	VST and VPL	Few C	Very few F	VF quartz grains	D and S
2Btg2	58–90	7.5YR 5/6 (matrix) 7.5YR 6/2 (mottles)	10YR 5/6 (matrix) 10YR 6/3 (mottles)	BL	VHA	FI	VST and VPL	N	Very few F	N	D and S
2Btg3	90–115	7.5YR 5/6 (matrix) 7.5YR 6/2 (mottles)	10YR 7/2 (matrix) 10YR 7/6 (mottles)	BL	VHA	FI	VST and VPL	N	N	N	D and S
2C1	115–167	7.5YR 5/8 (matrix) 7.5YR 4/3 (mottles)	10YR 7/2 (matrix) 10YR 7/6 (mottles)	GR	HA	WE ⟶ FR	SST and SPL	N	N	N	D and S
2C2	167–205	7.5YR 5/8 (matrix) 7.5YR 6/2 (mottles)	10YR 7/3 (matrix) 10YR 7/6 (mottles)	GR	HA	WE ⟶ FR	SST and SPL	N	N	N	D and S

Profile 3. Lelem series
A	0–18	7.5YR 4/4	10YR 5/4	SB ⟶ GR	HA	FR	ST and PL	Many F, M and C	Many F, M, C, T	N	C and S
Bt1	18–43	7.5YR 5/4	10YR 5/6	SB ⟶ GR	VHA	FI	VST and VPL	Common F, M and C	Many F, M, C, T	N	D and S
Bt2	43–73	7.5YR 5/4	10YR 5/6	AB	VHA	FI	VST and VPL	Common F, M and C	Few F, M, C, T	N	D and S
Btg	73–118/134	7.5YR 5/4 (Matrix) 7.5YR 3/3 (mottles)	10YR 6/4 (Matrix) 10YR 4/2 (mottles)	SB	VHA	FI	VST and VPL	Few M and C	Very few F, M, C, T	N	D and W
BCtg	118/134–175	7.5YR 6/2 (matrix) 7.5YR 3/2 (mottles) 7.5YR 5/6 (mottles)	10YR 6/4 (matrix) 10YR 5/6 (mottles) 10YR 6/8 (mottles)	SB ⟶ GR	VHA	FI	VST and VPL	Few M and C	Very few F, M, C, T	N	D and W

Profile 4. Ntengie series
Ap	0–27	7.5YR 3/3	10YR 4/4	SB	VHA	FI	SST and SPL	Many F, M and C	Many F, M, T	N	G and S
AB	27–50	7.5YR 5/6	10YR 4/4	SB ⟶ GR	HA	FI	SST and SPL	Many F and M	Many F, M, C, T	N	D and S
Cg	50–82	7.5YR 4/6 (matrix) 7.5YR 5/8 (mottles)	10YR 4/6 (matrix) 10YR 5/6 (mottles)	GR	LO	LO	NST and NPL	Many F and M	Few F and M	N	C and S
2AB	82–116	7.5YR 4/3	10YR 3/4	SB	HA	FI	ST and PL	Few M and C	Few F and M	N	D and S
2Btg	116–160	7.5YR 5/4	10YR 4/6	AB	HA	FI	ST and PL	Few M and C	Few F and M	N	C and S
2BC	160–210	7.5YR 5/6	10YR 5/6	SB ⟶ GR	HA	FI	SST and SPL	Few M and C	Few F and M	N	D and S

Profile 5. Bamengwi series
Ap	0–25	7.5YR 3/2	10YR 5/4	SB ⟶ GR	VHA	FR	ST and PL	Many F, M and C	Many F, M, T and few E	N	G and S
AB	25–44	7.5YR 5/6	10YR 6/4	GR	SSH	FR	SST and SPL	Many F and M	Many F, M, C, T, and few B	N	G and S
BCt	41–66	7.5YR 4/4	10YR 6/3	BL	VHA	FI	VST and VPL	Many F and M	Few F and M	N	C and W
2Cg1	66–102	10YR 7/6 (matrix) 7.5YR 7/8 (mottles)	10YR 7/3 (matrix) 10YR 6/8 (mottles)	WE SB	SHA	LO	NST and NPL	Few M and C	Few F and M	N	C and W
3Cg2	102–134	7.5YR 6/3 (matrix) 7.5YR 6/6 (mottles)	10YR 6/4 (matrix) 10YR 7/8 (mottles)	SB ⟶ GR	VHA	FR	ST and PL	Few M and C	Few F and M	N	D and S
4Cg3	134–162	7.5YR 6/4 (matrix) 7.5YR 5/8 (mottles)	10YR 7/3 (matrix) 10YR 7/8 (mottles)	SB ⟶ GR	SSH	FR	SST and SPL	Few M and C	Few F and M	N	D and S
5Cg4	162–205	7.5YR 6/2 (matrix) 7.5YR 5/8 (mottles)	10YR 7/3 (matrix) 10YR 7/8 (mottles)	SB ⟶ GR	VHA	FR	SST and SPL	Very few F	Few F and M	N	D and S

Note. BL blocky, SB subangular blocky, GR granular, AB angular blocky, SB ⟶ GR subangular blocky parting to granular, SHA slightly hard, HA hard, VHA very hard, SSH soft to slightly hard, WE weak, FR friable, FI firm, FRF friable to firm, LO loose, ST sticky, SST lightly sticky, PL plastic, SPL slightly plastic, VST very sticky, VPL very plastic, NST nonsticky, NPL nonplastic. For boundary, G gradual (5–15 cm), A abrupt, (0–2 cm), C clear (2–5 cm), D diffuse (>15 cm), S smooth, W wavy. For roots and biological features, F few, M many, C common (for abundance of roots), E earthworm channels, B burrows, T ant channels. For voids, F fine, M medium, C coarse, N none. For nodules and concretions, N none, F few, VF very few. Source: FAO [60].