14 



at an enhanced figure accompanied by loss of trees. 

 On a few estates in the F. M. S. and Sumatra I saw 

 instances of the use oi the original forest as "jungle 

 belts" (see rig. 40). These are strips of the jungle which 

 had been left between various parts of an estate in order 

 to prevent the spread of disease. The great objection to 

 these is that they offer excellent shelter for wild animals, 

 and later on they might harbour thieves. It would be 

 better to fell the jungle entirely and plant other trees, 

 such as Ficus, between the Hevea fields. 



b. Lalang soil. 



If rubber is to be planted on old lalang grounds, the 

 method of procedure is quite different. These lalang 

 grounds have not always been under that weed, they 

 were firstly covered with heavy jungle, that had in most 

 cases been cleared by the Chinese, in order to plant 

 Cassava, but sometimes the Malays cleared it for the 

 cultivation of paddy. Under the regulations, three crops 

 only of rice may be taken off the land. When they 

 have been harvested, the land is left to itself and then 

 becomes overgrown with the destructive grass which 

 is so prevalent in the Malay Archipelago. Lalang, 

 or Alang-Alang (Imperata Koenigii] is prejudicial to 

 nearly all cultivated crops, and yet this malign 

 influence cannot be entirely explained. A proof of the 

 strength of its growth is certainly given by the fact 

 that the roots are capable of piercing the living roots 

 of Hevea. In the Cassava plantations there is a con- 

 siderable undergrowth of Lalang in harvest time. Cassava 

 is said to exhaust the ground to a considerable degree, 



