151
RESULTS OF THE EXAMINATION OF SOIL FROM HONG KONG.
Imperial Institute No. M. 3283.
Date: 31st May, 1929.
Reference B. Top-soil, Chuk Shan Lung, Ma Wat Wai, Fanling; Uncultivated; pine & wild
trees, bamboo, ferns and grass growing on area.
Description: Yellowish loam.
RESULTS OF EXAMINATION.
Chemical analysis of "Fine earth" passing a 1 mm. sieve.
Available constituents i.e., portion soluble in 1%
Soluble in hydrochloric
acid
citric acid solution
Exchangeable bases: (Hissink method)
per cent.
per cent. lb: per acre.
per cent.
Lime Magnesia
...Cao
0.06
0.010
249
0.011
...MgO
0.09
0.016
398
0.008
Potash
..K20
0.18
-0.006
149
0.011
Soda
...Na,O
0.06
0.008
199
0.005
Ferric oxide
...Fe2O3
4.48
0.244
0.031
Alumina
Al2O3
5.25
0.190
0.016
Phosphoric acid
2
P205
0.11
0.001
།བ
25
Silica
..SiO 2
Nitrogen
...N
Organic carbon ...C
Organic matter*
Carbon dioxide ...CO2
Total
per cent. lb. per acre.
0.126
1.33
2.42
3135 33093
*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
12.3
Composition of clay fraction (0.002 mm. and under, separated by sedimentation).
per cent.
Titanium dioxide
Lime
Silica Alumina
Ferric oxide
Manganous oxide
Magnesia
Potash
Soda
Loss on ignition Phosphoric acid
...Sio
36.07
Al2O3
29.60
Fe2O
14.09
...TiO2 ...MnO
0.65
nil
Cao
0.22
...MgO
0.97
.K,0
1.52
...Na, O
1.28
;" -r
15.19
..P205
0.18
Total
99.77
Silica,
sio
Molecular ratio
=2.07.
Alumina, Al2O3