97
Table 1 Selected post-harvest soil properties from the previous legume-based cropping systems at Lilongwe and Dowa sites, Central Malawi
Site
Previous cropping system pH
Total N (%)
Available Mehlich-3 P (mg/kg) SOC
Depth (cm)
→
0–15
15–30
0–15
15–30
0–15
15–30
0–15
15–30
Lilongwe
Sole MZ
6.1
6.1
0.057
0.054
40.9
40.2
1.14
1.07
Sole MZ + 92 N
5.7
5.9
0.063
0.059
44.3
38.4
1.25
1.20
Sole CP
6.1
6.0
0.062
0.058
41.8
39.3
1.24
1.16
CP + MZ intercrop
6.0
6.1
0.065
0.054
45.5
38.6
1.31
1.08
Sole PP
6.1
6.1
0.059
0.054
45.0
37.4
1.17
1.09
PP + CP intercrop
5.9
6.0
0.057
0.055
41.2
39.2
1.14
1.12
PP + MZ intercrop
6.1
6.0
0.058
0.059
37.9
41.2
1.17
1.19
Dowa
Sole MZ
6.2
6.1
0.12
0.09
28.3
27.5
2.45
1.80
Sole MZ + 92 N
6.1
6.3
0.14
0.10
27.5
27.3
2.86
2.00
Sole CP
6.3
6.3
0.15
0.10
32.1
27.5
2.96
2.09
CP + MZ intercrop
6.2
6.4
0.14
0.09
34.2
29.3
2.88
1.90
Sole PP
6.3
6.2
0.13
0.10
32.1
24.7
2.65
2.04
PP + CP intercrop
6.1
6.0
0.14
0.10
28.3
25.4
2.85
1.95
PP + MZ intercrop
6.2
6.1
0.13
0.09
25.4
26.8
2.63
1.87
SOC
soil organic carbon, MZ
maize, CP
cowpea, PP
pigeon pea, 92 N = 92 Kg N Ha
−1
. Critical values: N = 1.13
(Landon 1991), P = 19 Mg/Kg
(Chilimba
2007), SOC = 0.88% (Chilimba 2007), pH = 5.5 (Chilimba 2007)
Integrated Soil Fertility Management Based on Pigeon Pea and Cowpea Cropping…