11 



changes to red. Since a sour soil is not suitable for 

 the growth of Hevea, it must be sweetened. This can 

 be done by draining, as will be seen subsequently. 



The usual practice is to apply lime to these soils, if 

 the clay is not too thick ; if the thickness exceeds two 

 feet, the soil is not suitable for Hevea. The best thing 

 to do is to mix the soil which is to be used for filling the 

 holes with lime before planting. Where it is only recognised 

 that lime is required after the trees have been planted, the 

 plantations should be dealt with as follows: near each 

 tree, three holes should be dug at a distance of one foot from 

 the tree for each year of its age, (i. e. for a tree 3 years 

 old, the holes should be 3 feet from the trunk) until 

 the subsoil water is reached, and then a quantity of 

 lime is thrown in. Trees which suffer from sour soil 

 may be easily recognised by the drooping appearance 

 of the crown. The top of the trunk and the upper and 

 lower branches droop and exhibit a grey dried up 

 appearance, and also the form of the root is characteristic 

 (see fig. 3). From the point where the root has been 

 cut from the stump, other parallel and horizontal roots 

 are developed (see fig. 4). 



These trees are not firm in the ground, and fall 

 sideways after a time ; straight trunks are essential for 

 satisfactory tapping and sloping trunks are objectionable. 



If an estate has to be planted up on clayey sour soil 

 with the aid of lime, it must be carefully examined some 

 months after the first liming. All trees which show the 

 above mentioned characteristics must be continually 

 dealt with until they show a healthy exterior. 



The consequences of liming are surprising. I was 

 shown over a plantation which looked so unhealthy 



