155
RESULTS OF THE EXAMINATION OF SOIL FROM HONG KONG.
Imperial Institute No. M. 3283.
Date: 31st May, 1929.
Reference: C. Top-soil, Chun Lung: Uncultivated; pine. & wild trees, ferns and grass
growing on area.
Description: Yellow clay 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 (Hisşink method)
per cent.
per cent. lb. per acre.
per cent.
Lime Magnesia
...Cao
0.01
0.010
227
0.008
...MgO
0.04.
0.009
204
0.010
Potash
...K20
0.06
0.003
68
0.006
Soda
...Na2O
0.27
0.010
227
0.013
Ferric oxide
...Fe, Ox
5.30
0.081
0.011
Alumina
Algos
9.53
*0.213
0.035
2 3
Phosphoric acid
Silica
P205 ...sio2
0.01
2
faint trace
Total
per cent.
lb. per acre.
Nitrogen
...N
0.110
Organic carbon ...C
1.50
2492 33988
Organic matter*
2.73
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.
( Carbon,
C
Atomic ratio Nitrogen, N
- 15.9
Composition of clay fraction (0.002 mm. and under, separated by sedimentation).
per cent.
Silica
Alumina
Ferric oxide
Titanium dioxide
...SiO2
..Al2O. ...Fe2O ...Tio.
34.53
32.88
13.09
2 3
0.90
2
Manganous oxide
...MnO
trace
Lime
...Cao
0.07
Magnesia
.MgO
0.36
Potash
...K,O
0.60
Soda
...Na2O
0.24
Loss on ignition
17.43
Phosphoric acid
...P203
0.13
2
Total
100.23
(Silica,
Molecular ratio
SiO2 Alumina, Al,03
=1.78.