Ecological and Edaphic Drivers of Yam Production in West Africa
Table 3
Average nutrients removed from the soil by D. alata, D. cayenensis, and D. rotundata tubers in western Nigeria and central Côte d’Ivoire applied with K fertilizer plus basal dressing of N and P and NPK fertilizer, respectively.
Species
Year
Nutrient extracted (kg ha−1 dry matter) basis
N
P
K
Ca
Mg
D. alata
1976
65.3 ± 4.1
8.6 ± 0.5
82.4 ± 5.2
1.4 ± 0.1
4.1 ± 0.3
D. cayenensis
38.4 ± 1.8
5.4 ± 0.3
50.2 ± 2.3
1.1 ± 0.1
3.6 ± 0.2
D. rotundata, cv Efuru
44.9 ± 2.7
5.3 ± 0.3
50.9 ± 3.0
1.1 ± 0.1
3.1 ± 0.2
D. rotundata, cv Aro
40.0 ± 2.1
5.1 ± 0.3
44.2 ± 2.3
1.0 ± 0.1
3.2 ± 0.3
D. alata
1975
47.5 ± 4.1
6.3 ± 0.5
59.9 ± 5.1
1.0 ± 0.1
3.0 ± 0 .3
D. cayenensis
105.9 ± 3.0
14.8 ± 4.2
138.5 ± 3.9
2.9 ± 0.1
10.1 ± 0.3
D. rotundata, cv Efuru
110.4 ± 11.8
12.9 ± 1.4
125 ± 13.4
2.8 ± 0.3
7.6 ± 0.8
D. rotundata, cv Aro
82.4 ± 7.9
10.5 ± 1.0
91.0 ± 8.8
2.0 ± 0.2
6.9 ± 0.6
D. alata
1974
128.3 ± 7.1
16.9 ± 0.9
161.7 ± 8.9
2.8 ± 0.2
7.9 ± 0.4
D. cayenensis
138.8 ± 3.9
19.4 ± 0.5
181.5 ± 5.1
3.8 ± 0.1
13.1 ± 0.4
D. rotundata, cv Efuru
155.3 ± 5.9
18.2 ± 0.6
176.1 ± 6.2
3.9 ± 0.1
10.7 ± 0.4
D. rotundata, cv Aro
140.3 ± 3.4
18.1 ± 0.4
154.9 ± 3.8
3.4 ± 0.2
11.2 ± 0.3
D. alata
2003
216
10
178
27
14
D. rotundata
66
3
104
25
9
Dataset for 1974–1976 (N = 5 ± SE, with no statistical significance) was adapted from Obigbesan and Agboola [63]. Dataset for 2003 was obtained from Diby et al. [64].
