Dry Matter Production, Nutrient Cycled and Removed, and Soil Fertility Changes in Yam-Based Cropping Systems with Herbaceous Legumes in the Guinea-Sudan Zone of Benin

Table 4

Initial soil characteristics at the beginning of the experiment at 0–10 and 10–20 cm layers in four village sites (Miniffi, Gomè, Gbanlin, and Akpéro) with 32 farmers, Benin.

	Akpéro		Gbanlin		Miniffi		Gomè
Depth (cm)	0–10	10–20	0–10	10–20	0–10	10–20	0–10	10–20
	“Plinthosols”		“Plinthosols”		“Luvisols ferriques”		“Luvisols ferriques”
Clay%	6.58	7.281	5.788	5.66	6.758	6.51	6.828	7.861
Silt%	11.66	11.798	5.808	5.55	6.828	7.081	16.071	17.36
Sand%	81.76	80.920	88.402	88.79	86.412	86.408	77.10	74.778
C%	1.31	1.050	0.69	0.788	0.80	0.64	0.65	0.54
N%	0.112	0.092	0.059	0.081	0.081	0.056	0.073	0.062
C/N	11.70	11.43	11.70	9.68	9.83	11.43	8.90	8.69
OM%	2.25	1.81	1.19	1.36	1.37	1.10	1.12	0.93
PH	6.7	6.7	6.6	6.3	6.7	6.8	6.6	6.6
Bray P	20.125	14.875	7.00	4.00	11.00	3.012	7.987	4.00

C%: soil carbon concentration; N%: soil nitrogen concentration; OM% (=1.72 × C%): soil organic matter content; C/N: index of biodegradability or ratio of soil carbon to nitrogen; Bray P (mg kg⁻¹): soil phosphorus.