AGRICULTURAL BULLETIN 



OF THE 



STRAITS 



AND 



- FEDERATED MALAY STATES. 



No. 1.] JANUARY, 1909. [Vol. VIII. 



THE TREATMENT OF AOID SOILS FOR RUBBER 

 AND OTHER CULTIVATIONS. 



A series of experiments have been begun by the Department of 

 Agriculture on some low lying fiat land which has abnormally acid soil, 

 rendering it unfavourable for the rapid growth of root growth of rub- 

 ber or other cultivated plants. 



The presence of a too large proportion of acid in peaty soils is due 

 to the existence of a large proportion of humic acid which is a brown 

 or black substance produced by decaying vegetable matter. This de- 

 composition is greatly facilitated by heat, air, and moisture and by the 

 presence of putrefying nitrogenous matter. The conditions in many 

 clearings in Malaya are therefore specially suited to the formation of 

 an excess of humic acid which exists in many places to such an extent 

 that the roots of young rubber are not able to grow and the plants 

 grow without vigour and in some cases succumb. 



Such soils are physically and in other respects, most suitable for 

 healthy and rapid growth of rubber and when the amount of acid has 

 been reduced they often produce exceptionally fine rubber. 



The question of the neutralisation of such soils in the shortest 

 time is of great importance. The only method used at present is to 

 allow T the sun free access to the soil and by this means and plentiful 

 drainage to gradually eliminate a proportion of the acid. 



This is however a lengthy and not always successful method and 

 a much quicker plan is to add such proportion of basic substance such 

 as lime as is needed to neutralize the acid in the soil. 



A very large supply of natural phosphate is being extracted from 

 Christmas Island and can be delivered comparatively cheaply at S. S. 

 and F. M. S. ports. 



This raw phosphate not converted into the superphosphate will 

 be tried on acid soils. The advantage in using this manure is that the 

 arw phosphate i.e., phosphatic rocks exactly as they are obtained in 



