Soil Assessment along Toposequences in Rural Northern Nigeria: A Geomedical Approach

Table 2

Chemical soil characteristics of the soils of the study area.

Morphological unit	Soil type	Horizon	pH	OC	Ca	Mg	K	P	CEC	BS
				%	Cmol kg^−1			mg kg^−1	cmol kg^−1	%
Upper pediment	Haplic Lixisols; (chromic)	Ap	6.0	0.8	2.8	0.9	0.3	3.0	6.7	62.9
		Bt*	4.9	0.2	3.7	1.6	0.2	0.0	11.1	50.4
		2Btw	4.8	0.1	2.7	0.8	0.3	0.0	8.0	50.3
	Haplic Lixisols; (colluvic)	Ap	5.3	1.0	3.1	0.5	0.2	2.0	6.4	60.7
		2Btw*	4.8	0.5	5.3	1.4	0.1	0.0	11.9	57.9
		2Bwo	4.7	0.2	3.7	1.0	0.4	0.0	10.1	50.7
	Haplic Lixisols	Ap	5.6	0.7	4.7	0.8	0.3	8.0	9.8	59.1
		Bt*	5.2	0.7	5.6	1.2	0.1	4.0	12.5	56.0
Lower pediment	Haplic Acrisols; (arenic)	Ap	5.7	1.0	1.3	0.2	0.1	2.0	5.3	62.3
		Bo	4.4	0.4	1.7	0.4	0.1	1.0	4.1	38.6
		Bto*	4.2	0.5	1.4	0.6	0.1	1.0	8.2	26.6
		2Bo	4.7	0.1	4.0	1.6	0.1	0.0	7.9	27.2
	Haplic Acrisols	Ap	5.9	1.2	2.8	0.9	0.2	3.0	12.9	61.2
		Bto*	4.1	0.6	3.4	1.3	0.4	1.0	13.2	31.6
		Bwo	4.7	0.4	2.9	0.3	0.4	1.0	12.5	44.3
	Haplic Acrisols; (arenic)	Ap	5.6	0.7	1.2	0.5	0.2	1.0	7.4	46.3
		Bl	5.4	0.3	1.9	1.0	0.1	1.0	2.9	65.8
		Bt*	4.9	0.3	2.1	0.5	0.4	0.0	8.3	40.0
		2Bt	4.7	0.1	4.7	0.6	0.3	0.0	8.0	37.3
River valley	Gleyic Fluvisols; (dystric, siltic)	Ap	4.0	1.0	0.9	0.4	0.0	2.0	8.8	19.3
		Bsg*	4.2	0.4	1.7	0.4	0.1	2.0	11.1	26.6
	Gleyic Fluvisols; (dystric, siltic)	Ap	5.1	0.4	2.3	1.0	0.1	1.0	8.4	40.5
		Bog*	4.6	0.7	2.2	0.7	0.0	2.0	8.5	35.5
	Gleyic Fluvisols; (arenic)	Ap	4.0	0.6	1.5	0.2	0.1	2.0	6.8	26.9
		Bg	4.3	0.3	1.6	0.3	0.1	5.0	5.5	36.0
		2Bsg*	4.8	0.2	2.5	0.4	0.1	0.0	6.1	50.6
Lower plain	Pisoplinthic Acrisols; (chromic)	Ap	4.7	1.2	2.9	0.7	0.1	2.0	9.8	38.5
		Bto*	4.3	0.5	2.7	0.7	0.1	1.0	11.0	32.1
		2Bwo	4.2	0.4	1.6	0.4	0.1	1.0	9.6	21.8
	Gleyic Acrisols; (siltic)	Ap	4.2	0.8	1.9	0.6	0.0	4.0	9.6	26.9
		Bto*	4.3	0.7	1.8	0.7	0.0	3.0	8.0	31.6
	Pisoplinthic Acrisols; (chromic)	Ahc	5.0	1.1	3.7	0.9	0.1	1.0	12.5	38.0
		Bto*	4.2	0.4	2.5	0.4	0.0	0.0	9.7	30.5
		2Bw	4.0	0.3	1.9	0.4	0.0	0.0	10.3	22.7
Upper plain	Haplic Plinthosols; (dystric)	Ap	4.7	1.2	2.4	0.6	0.1	3.0	9.1	34.1
		Bv*	4.2	0.8	1.3	0.2	0.0	1.0	8.5	17.9
	Haplic Plinthosols; (hyperdystric, clayic)	Ahc	4.2	1.3	2.5	0.7	0.2	1.0	13.5	26.2
		Btv*	4.0	0.4	0.9	0.1	0.0	5.0	12.0	6.3
		Bov	4.0	0.4	0.4	0.0	0.2	0.0	12.1	5.2

∗Diagnostic horizons.