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 10

(a) Soil characteristics at the end of the experiment (December 2005), 0–10 and 10–20 cm layers, on 1-year fallow of Andropogon gayanus-yam rotation (T0), 32 farmers, four village sites, Benin. (b) Soil characteristics at the end of the experiment (December 2005), 0–10 and 10–20 cm layers, on maize-yam rotation (TM), 32 farmers, four village sites, Benin. (c) Soil characteristics at the end of the experiment (December 2005), 0–10 and 10–20 cm layers, on A. histrix/maize intercropping-yam rotation (TMA), 32 farmers, four village sites, Benin. (d) Soil characteristics at the end of the experiment (December 2005), 0–10 and 10–20 cm layers, on M. pruriens/maize intercropping-yam rotation (TMM), 32 farmers, four village sites, Benin. (e) Soil characteristics at the end of the experiment (December 2005), 0–10 and 10–20 cm layers, four yam-based cropping systems (1-year fallow of Andropogon gayanus-yam rotation; maize-yam rotation; A. histrix/maize intercropping-yam rotation; M. pruriens/maize intercropping-yam rotation), 32 farmers, four village sites, Benin (all sites confounded).

(a)

	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%	5.927	6.101	5.276	5.227	6.078	6.143	6.004	6.239
Silt%	10.482	10.755	5.425	5.446	6.329	6.568	15.950	16.089
Sand%	83.587	83.143	89.293	89.325	87.587	87.287	78.046	77.671
C%	0.996	0.909	0.686	0.672	0.756	0.723	0.625	0.587
N%	0.080	0.087	0.0575	0.059	0.061	0.061	0.0588	0.058
C/N	12.523	10.911	12.00	11.389	12.438	11.928	10.821	10.211
OM%	1.713	1.563	1.180	1.157	1.301	1.247	1.076	1.010
PH	6.364	6.095	6.020	6.278	5.934	6.020	5.934	5.848
Bray P	20.440	18.880	5.646	5.743	9.073	6.688	5.668	3.693
K	0.385	0.366	0.407	0.283	0.329	0.214	0.203	0.201

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-soil): soil phosphorus; K cmol kg⁻¹: soil potassium.

(b)

	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%	5.363	5.666	5.020	5.006	5.913	5.811	5.780	5.959
Silt%	10.820	10.951	5.393	5.573	6.271	6.358	16.226	16.348
Sand%	83.816	83.381	89.581	89.423	87.815	87.834	77.997	77.697
C%	1.015	0.9165	0.669	0.655	0.754	0.684	0.617	0.557
N%	0.089	0.109	0.066	0.078	0.075	0.082	0.072	0.071
C/N	11.419	8.575	10.113	8.520	10.223	8.355	8.591	7.786
OM%	1.746	1.576	1.150	1.127	1.297	1.176	1.062	0.959
PH	6.993	6.733	6.650	6.897	6.555	6.650	6.555	6.441
Bray P	22.610	21.750	7.031	7.604	8.041	6.024	8.041	6.024
K	0.582	0.493	0.466	0.353	0.376	0.239	0.271	0.235

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-soil): soil phosphorus; K cmol kg⁻¹: soil potassium.

(c)

	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%	6.509	6.752	5.455	5.999	6.245	5.882	5.567	5.390
Silt%	10.581	10.811	5.513	5.608	6.310	6.396	15.85	15.866
Sand%	82. 910	82.438	89.033	88.394	87.445	87.721	78.748	78.744
C%	1.1248	1.0583	0.732	0.685	0.781	0.771	0.635	0.608
N%	0.107	0.124	0.073	0.084	0.084	0.092	0.079	0.076
C/N	10.707	8.654	10.115	8.197	9.300	8.417	8.082	8.006
OM%	1.935	1.820	1.260	1.178	1.344	1.326	1.092	1.046
PH	7.371	7.221	7.112	7.237	7.034	7.087	6.997	7.031
Bray P	23.890	22.930	8.929	8.540	9.364	6.900	9.364	6.900
K	0.687	0.604	0.509	0.436	0.452	0.297	0.332	0.298

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-soil): soil phosphorus; K cmol kg⁻¹: soil potassium.

(d)

	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%	6.180	6.539	5.724	6.045	6.371	6.191	5.561	5.440
Silt%	10.556	10.789	5.519	5.579	6.330	6.373	15.714	15.841
Sand%	83.264	82.673	88.758	88.376	87.299	87.436	78.725	78.719
C%	1.244	1.150	0.757	0.729	0.819	0.810	0.655	0.619
N%	0.127	0.138	0.083	0.086	0.088	0.094	0.085	0.078
C/N	9.959	8.425	9.224	8.545	9.239	8.457	7.707	7.944
OM%	2.140	1.978	1.303	1.253	1.409	1.393	1.126	1.064
PH	7.225	7.162	6.963	6.912	6.875	6.975	7.062	6.888
Bray P	23.110	22.700	10.015	10.393	11.665	7.755	11.665	7.755
K	0.746	0.663	0.552	0.494	0.479	0.338	0.367	0.315

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-soil): soil phosphorus; K cmol kg⁻¹: soil potassium.

(e)

Soil characteristics	Depth	T0	TM	TMA	TMM	LSD
Clay%	0–10 cm	5.821	5.519	5.944	5.959	0.111
	10–20 cm	5.928	5.611	6.006	6.054	0.124
Silt%	0–10 cm	9.546	9.678	9.522	9.530	ns
	10–20 cm	9.714	9.807	9.670	9.645	ns
Sand%	0–10 cm	84.628	84.802	84.534	84.511	ns
	10–20 cm	84.357	84.584	84.324	84.301	ns
C%	0–10 cm	0.766	0.764	0.818	0.869	0.037
	10–20 cm	0.723	0.703	0.780	0.827	0.033
N%	0–10 cm	0.064	0.076	0.086	0.095	0.003
	10–20 cm	0.066	0.085	0.094	0.099	0.004
C : N	0–10 cm	11.947	10.087	9.551	9.032	0.272
	10–20 cm	11.109	8.309	8.319	8.343	0.211
MO%	0–10 cm	1.317	1.313	1.408	1.495	0.063
	10–20 cm	1.244	1.209	1.342	1.422	0.057
Bray P (mg kg^−1)	0–10 cm	10.210	11.840	13.430	14.346	1.126
	10–20 cm	8.750	10.660	11.410	12.290	1.217
K^+ cmol kg^−1	0–10 cm	0.331	0.424	0.495	0.536	0.026
	10–20 cm	0.266	0.330	0.409	0.453	0.028
PH water	0–10 cm	6.063	6.688	7.129	7.031	0.055
	10–20 cm	6.060	6.680	7.144	6.984	0.053

Means with the same letter within row are not significantly different ().
C%: soil carbon concentration; N%: soil nitrogen concentration; OM% (=1.72 × C%): soil organic matter content; C : N: ratio of soil carbon to nitrogen; Bray P (mg/kg-soil): soil phosphorus; K⁺ cmol kg⁻¹: soil potassium; LSD: least square difference at 5%; SD: standard deviation.
T0 (control 1): one-year fallow-yam rotation; TM (control 2): maize-yam rotation; TMA: A. histrix/maize intercropping-yam rotation; TMM: M. pruriens/maize intercropping-yam rotation; LSD: least square difference at 5%; ns: nonsignificant.
Data are the means.