260 
Chemical Composition. 
Moisture 3.000 
Organic matter and combined water 6.000 
Oxide of iron and manganese 5. 200 
Oxide of alumina !3-049 
Lime o. 160 
Magnesia 0.490 
Potash 0.401 
Phosphoric acid 0.089 
Soda 0.137 
Sulphuric acid 0.068 
Chlorine 0.006 
Sand and silicates 71.400 
100.000 
Containing nitrogen 0.162 
Equal to ammonia °- I 95 
Lower oxide of iron Trace 
Acidity Much 
Citric soluble potash 0.025 
Citric soluble phosphoric acid Trace 
4. Swamps. — The cultivation of rubber in such areas has dur- 
ing the last year shown a considerable increase. Providing the 
draining and liming of the soils are efficiently carried out there 
seems no reason why continued satisfactory growth should not 
be obtained on such land. 
The drainage should be very thorough so as to allow a good 
percolation of air and water through the otherwise sour soils. 
In some cases each rubber tree should have a separate drainage 
system, the drains being two or more feet wide and 3 to 4 feet 
deep, the material from them being heaped up near the rubber 
tree. In other cases each line of rubber trees may be separately 
drained. When the drains are sufficiently large and the soil from 
them is heaped around the rubber, a dry soil is ultimately obtained, 
in areas which have hitherto been too swampy for any cultivation 
except paddy. The following analysis will show the general com- 
position of such a soil : 
ANALYSIS OF SWAMPY RUBBER SOIL FROM THE SOUTHERN PRO- 
VINCE (black soil). 
Median ical Co m position. 
Per Cent. 
Fine soil passing 90 mesh 59 .00 
Fine soil passing 60 mesh 36.00 
Medium soil passing 30 mesh 1.00 
Coarse sand and small stones 4.00 
100.00 
