Sessional_Paper_1929 — Page 179

171

RESULTS OF THE EXAMINATION OF SOIL FROM HONG KONG.

Imperial Institute No. M. 3283.

Date: 31st May, 1929.

Reference: G. Top-soil; Shek Kwu Lung; Uncultivated; pine and wild trees, ferns and

grass growing on area.

Description Yellowish-brown loam.

RESULTS OF EXAMINATION.

Chemical analysis of "Fine earth" passing a 1 mm. sieve.

Available constituents i.e., portion soluble in 1%

citric acid solution

Soluble in hydrochloric acid

Exchangeable bases (Hissink method)

per cent.

per cent. lb. per acre.

per cent.

Lime Magnesia

Potash

...Cao

..MgO ...K2O

0.10

0.008

174

0.012

0.36

0.015

326

0.019

0.20

0.008

174

0.007

2

Soda

...Na.O

0.16

0:008

174

0.009

Ferric oxide

Alumina

Phosphoric acid Silica

...Fe2O3 A1,03 P2O ..SiO.

2 5

2

2

5.75

0.067

trace

11.58

0.208

0.032

· 0.03

slight trace

Total

per cent..

Ib.

per acre.

Nitrogen

...N

0.183

3971

Organic carbon ...C

1.79

38843

Organic matter*

3.26

Carbon dioxide ...CO,

*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

11.4.

Composition of clay fraction (0.002 mm. and under, separated by sedimentation).

per cent.

Silica Alumina

...SiO 2

34.70

.....ALO 3

31.60

Ferric oxide

...Fe20

12.63

Titanium dioxide

...Tio,

0.87

2

Manganous oxide

...MnO

0.09

Lime

...Cao

0.12

Magnesia

MgO

0.59

Potash

...K.O

0.96

Soda

...Nã2O

0.12

2

Loss on ignition .......

17.89

Phosphoric acid

...P2O

0.54

2

Total

100.11

Silica.

Molecular ratio

SiO2 Alumina, Al,03

- 1.86.