AGRICULTURAL BULLETIN 
OP THE 
STRAITS 
AND 
FEDERATED MALAY STATES. 
No. 10.] OCTOBER 1909. [Von. VIII 
RUBBER CULTIVATION ON SO CALLED 
PEAT SOIL. 
By H. N. Ridley. 
In many parts of the Malay Peninsula usually in the 
vicinity of large tidal rivers, we find a somwhat peculiar 
soil formation popularly known here as peat formation. It 
consists exclusively of dead timber roots and decayed 
leaves, to a depth sometimes of as much as twenty feet. 
Often no trace of clay, stone or other mineral matter is to 
be seen in it. The formation appears even if deep to be of 
comparatively modern date, geologically speaking. Before 
being cleared for planting it is seen to be covered with dense 
wet forests, in which grow a number of somewhat peculiar 
or local plants mixed with many trees which also occur on 
more ordinary soil. A characteristic tree is the Kempas, 
Cumpassia malaccemls, abundant too is the well known red 
stemmed palm, Ci/rtostachys lacca and the ground is often 
covered with an abundance of Gingers (Scitamineae) and 
ground orchids. Walking through these woods one often 
sinks deeply into a mass of wet decaying leaves, over and 
through which lie the great roots of the big trees. Below 
this great mass of decaying vegetation is usually a greasy 
blue clay lying at various depths and apparently mainly old 
Mangrove* mud and over which this forest has gradually 
grown. When felled and burnt this so-called peat after a 
period of exposure commences to shrink, the surface of the 
ground often soon falling a foot or more. The exposed 
