RUBBER PLANTING 105 



drainage is required. Small drains about one and a 

 half feet in width and depth are carried across the 

 slopes with a fall of from I in 15 to i in 25. These 

 are made to discharge into any natural ravines or 

 watercourses which may occur. The distance between 

 the drains varies, according to the slope, from 100 feet 

 down to 20 feet or less. The earth removed in digging 

 is thrown out on the lower side of the drain. Loss of 

 soil may be further checked by interrupting the drains 

 with catch pits at frequent intervals. On very rocky 

 hillsides draining may be impracticable. In this case 

 some kind of terracing is frequently attempted by 

 building low walls of boulders below the trees. This 

 method is strongly to be recommended where drains 

 cannot be cut. 



Irrigation has been little practised in the cultivation 

 of Hevea. In a dry climate the tree appears to suffer 

 more from the effects of sun and wind upon its young 

 branches and leaves than from lack of water in the soil. 

 Experiments in growing Hevea under irrigation in the 

 dry zone of Ceylon have so far been unsuccessful, 

 though it is possible that they might have fared better 

 if an effective wind-break could have been found. 



The laying out of roads and paths leading to the 

 different sections of the estate is an operation which 

 should be undertaken at the same time as the tracing 

 of the drains, in order that the necessary culverts and 

 bridges may be provided for. Except in the case of 

 the principal tracks, little road-making is necessary 



