Sessional_Paper_1929 — Page 175

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RESULTS OF THE EXAMINATION OF SOIL FROM HONG KONG.

Imperial Institute No. M. 3283.

Date: 31st May, 1929.

Reference F. Top-soil; Tai Long Wan, Lo Kong; Shek O; Cultivated, fair crop of padi

growing on area.

Description: Pinkish-brown-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

MgO

0.04

0.023

680

0.034

-0.14

0.036

874

0.029

Potash

...K2O

2

0.13

0.008

194

0.008

Soda

Na2O

0.06

0.022

534

0.022

Ferric oxide

Fe 0,

4.03

0.085

Alumina

....A1,02

7.75

0.001

0.092

Phosphoric acid

2

P20,

0.04

trace

Silica

...SiO2

Total

per cent.

lb.

per acre.

Nitrogen

..N

0.060

Organic carbon ...C

0.657

1456 15945

Organic matter*

1.19

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.

Carbon, C

Atomic ratio

12.8

Nitrogen, N

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

per cent.

Silica Alumina

Ferric oxide

...Sio,

.AI2O; ...Fe2O3

2

38.58 30.09

2 3

10.30

Titanium dioxide

...Tio

0.40

Manganous oxide

..MnO

trace

Lime

...Ca(

0.10

Magnesia

...MgO

0.49

Potash

K2O

1.36

2

Soda

Loss on ignition Phosphoric acid

...Na2O

0.44

17.85

0.12

2

A

Total

99.73

Silica,

SiO 2

Molecular ratio

=2.18.

Alumina, Al2O3