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 8
Nitrogen, phosphorus, and potassium content (kg ha−1) dry matter of plant parts removed in the crop harvest and those returned to the soil in yam-based cropping systems (2002-2003 and 2004-2005 cropping seasons, four cropping system treatments, four village sites, 32 farmers, Benin).
2002-2003 cropping seasons
2004-2005 cropping seasons
T0
TM
TMA
TMM
LSD
SD
T0
TM
TMA
TMM
LSD
SD
Plant nutrients removed (kg ha−1)
Yam tubers
N
19.35
14.57
27.37
27.84
1.95
2.98
16.49
11.48
30.41
30.47
2.08
3.18
P
1.99
1.49
2.81
2.86
0.20
0.31
1.69
1.18
3.12
3.13
0.21
0.33
K
21.39
16.10
30.25
30.77
2.16
3.30
18.23
12.70
33.61
33.68
2.30
3.52
Maize grains
N
0.00
34.88
34.43
33.38
2.27
3.47
0.00
31.52
27.68
26.71
2.03
3.11
P
0.00
5.30
5.24
5.08
0.35
0.53
0.00
4.79
4.21
4.06
0.31
0.47
K
0.00
4.34
4.28
4.15
0.28
0.43
0.00
3.92
3.44
3.32
0.25
0.39
Plant nutrients recycled (kg ha−1)
Yam shoots
N
14.01
10.54
19.81
20.15
1.41
2.16
11.72
8.16
21.60
21.65
1.48
2.26
P
1.91
1.44
2.70
2.75
0.19
0.29
1.30
0.91
2.40
2.41
0.16
0.25
K
17.57
13.22
24.85
25.28
1.77
2.71
14.65
10.20
27.01
27.06
1.85
2.83
Fallow stover
N
47.63
0.00
0.00
0.00
3.86
5.91
47.03
0.00
0.00
0.00
4.22
6.46
P
5.26
0.00
0.00
0.00
1.23
1.89
5.09
0.00
0.00
0.00
1.27
1.94
K
19.90
0.00
0.00
0.00
2.16
3.30
19.49
0.00
0.00
0.00
1.98
3.03
Maize stover
N
0.00
31.87
31.43
30.47
2.45
3.75
0.00
33.45
29.35
28.28
2.60
3.97
P
0.00
4.56
4.51
4.37
0.39
0.60
0.00
4.65
4.08
3.95
0.45
0.68
K
0.00
17.48
18.57
16.76
1.86
2.84
0.00
17.42
15.30
14.80
1.42
2.17
Aeschy. stover
N
0.00
0.00
115.93
0.00
6.63
10.14
0.00
0.00
107.70
0.00
9.34
14.28
P
0.00
0.00
8.15
0.00
0.97
1.49
0.00
0.00
8.76
0.00
0.69
1.05
K
0.00
0.00
36.25
0.00
1.33
2.03
0.00
0.00
34.53
0.00
1.70
2.60
Mucuna stover
N
0.00
0.00
0.00
138.92
6.53
9.99
0.00
0.00
0.00
133.25
5.28
8.07
P
0.00
0.00
0.00
11.40
1.81
2.77
0.00
0.00
0.00
11.11
1.61
2.46
K
0.00
0.00
0.00
39.73
1.51
2.31
0.00
0.00
0.00
39.68
1.78
2.72
Means with the same letter within row are not significantly different (). 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; SD: standard deviation; LSD: least square difference at 5%.
