RECLAMATION OP THE SOIL. 31 



Where extensive areas are to be irrigated, the channels 

 and trenches must be carefully laid out, with a suitable 

 fall, so as to prevent the bursting of the channels and 

 the silting up of the trenches. 



4. Treatment of Excessive Accumulations of 

 Vegetable Matter. 



Cases occur in which accumulations of vegetable 

 matter have to be disposed of, before the formation of a 

 wood can be taken in hand. Such accumulations may 

 be objectionable because they are so thick that the 

 seedlings cannot reach the mineral soil within a reason- 

 able space of time, and run the risk of drying up ; or 

 they may have become acid, or bituminous ; again they 

 may be accompanied by swampiness, or be liable to dry 

 up too quickly. 



The following cases specially interest the forester : 



a. Peat Bogs. 



To render a peat bog fit for the growth of timber 

 trees, one or all of the following operations must be 

 carried out : 



(1.) Draining. 



(2.) Kemoval of at least a portion of the peat. 



(3.) Mixing the peat with mineral soil. 



The draining is done in the manner described above ; 

 it is, however, desirable to do this gradually, so that the 

 layers of peat may dry by slow degrees, to prevent 

 extensive cracks from forming. The feeders should at 

 first be of a moderate depth, and gradually deepened, 

 until the mineral soil is reached. 



