54
Table 5.2 Soil initial conditions used for evaluation of APSIM and DSSAT crop models. Soil samples were collected from experimental sites in December
2008 from the Nkayi district
Parameter
Soil layers (cm)
Low carbon soil
Medium carbon soil
High carbon soil
PAWC to rooting depth (65 mm)
PAWC to rooting depth (72 mm)
PAWC to rooting depth (92 mm)
0–15
15–30 30–45 45–60 60–75 0–15
15–30 30–45 45–60 60–90 0–15
15–30
30–
60
60–90 90–120
Organic carbon (%)
0.33
0.27
0.21
0.19 0.09
0.49
0.47 0.43 0.32
0.28
0.89
0.86
0.76 0.57
0.36
NO
3 -N
a
(ppm)
1.70
1.21
1.10
0.11 0.11
2.13
2.00 1.71 0.43
0.43
2.95
2.86
2.84 0.69
0.55
LL 15
a
(mm/mm)
0.15
0.18
0.23
0.24 0.27
0.15
0.18 0.23 0.24
0.27
0.15
0.18
0.23 0.24
0.27
DUL
a
(mm/mm)
0.28
0.30
0.30
0.30 0.32
0.28
0.30 0.30 0.30
0.32
0.28
0.30
0.30 0.30
0.32
SAT
a
(mm/mm)
0.38
0.40
0.40
0.40 0.42
0.38
0.40 0.40 0.40
0.42
0.38
0.40
0.40 0.40
0.42
Bulk density (g cm
−3
) 1.43
1.42
1.55
1.55 1.61
1.43
1.42 1.55 1.55
1.61
1.43
1.42
1.55 1.55
1.61
Source: Masikati (2011)
a
NO
3 -N
nitrate-nitrogen, LL 15
crop lower limit, DUL
drained upper limit, SAT
saturation, PAWC
plant available water capacity
P. Masikati et al.