159
RESULTS OF THE EXAMINATION OF SOIL FROM HONG KONG.
Imperial Institute No. M. 3283.
Date: 31st May, 1929.
Reference: D. Top-soil, Chung Uk Chun, Tin Shum, Castle Peak; Uncultivated; large wild
trees, bamboo, ferns and grass growing on area.
Description: Grey sandy loam.
RESULTS OF EXAMINATION.
Chemical analysis of "Fine earth" passing a 1 mm. sieve.
Soluble in hydrochloric acid
Available constituents i.e., portion soluble in 1% citric acid solution
Exchangeable bases (Hissink method)
per cent.
per cent. lb. per acre.
per cent.
Lime Magnesia
...Cao
0.14
0.099
2804
0.132
...MgO
0.04
0.003
35.
0.016
Potash
K2O
2
0.09
0.008
227
0.011
Soda
...Na2O
0.11
2
0.013
368
0.006
Ferric oxide
..Fe2Os
0.73
0.091
Alumina
...Al,O,
0.009
3.11
2 3
0.162
Phosphoric acid
Silica
P2 .Sio
5
0.12
0.046
1303
2
Total
per cent.
lb. per acre.
Nitrogen
...N
0.112
Organic carbon ...C
1.31
3173 37110
Organic matter*
2.38
Carbon dioxide ....CO2
*Obtained by multiplying the figure for organic carbon by
100
The figures for lb. per acre of the various constituents in the above table are calculated for a depth of 9 inches of soil, the apparent specific gravity of the soil being taken into consideration.
Atomic ratio
Carbon, C Nitrogen, N
13.6
43.92
32.11
3
5.95
0.64
2
Silica
Composition of clay fraction (0.002 mm. and under, separated by sedimentation).
Alumina
Ferric oxide
Titanium dioxide
...SiO 2 ...Alg
Algo ...Fe2O3 ...Tio,
per cent.
Manganous oxide
.....MnO
0.13
Lime
...Cao
0.37
Magnesia
..MgO
0.44
Potash
...K2O
1.18
2
Soda
Na,O
none
Loss on ignition
14.96
Phosphoric acid
...P205
0.70
2
Total
100.40
Silica,
SiO 2
Molecular ratio
Alumina, Al2O3 -2.32.