Fig. 2.7 Median and upper and
lower quartiles of clay content,
soil dry bulk density (t m
−3
), and
soil total available water capacity
for Allophanic Soils in the NZ
Soil Data Repository
Table 2.1 Typical example of
physical properties of an
Allophanic Soil: Horotiu series
(Typic Orthic Allophanic Soil)
SB09944 (SWAMP)
Horizon Depth cm Sand % Silt % Clay % Dry bulk density (t m
−3
) RAW
a % TAW
a %
Ap1
0–6
33
48
17
0.86
13
30
Ap2
6–17
33
49
16
0.82
14
24
AB
17–31
35
47
16
0.80
15
25
Bw1
31–55
46
24
29
0.83
9
15
Bw2
55–73
53
28
18
0.82
7
10
Bw3
73–91
45
21
32
0.81
5
10
2Cu(g)
91–107
63
26
9
0.99
10
12
2Cu
107–130
93
5
1
1.46
2
5
a RAW = readily available water, TAW = total available water, both in % by volume
Fig. 2.8 Median and upper and
lower quartiles of soil pH, organic
carbon and P retention for
Allophanic Soils in the NZ Soil
Data Repository
32
2 Allophanic Soils