152 AUTIFICIAL FOltMATlUN Ol' WOODS. 



some instances by draininfi; or irrigating, and in exceptional 

 cases by manuring. 



Loosening the soil secures the following advantages: — 

 (1.) It enables the roots to spread more readily, and 

 to penetrate deeper into the ground, thus rendering 

 the young plant more independent of variations of 

 moisture in the surface soil. 

 (2.) It effects a mixture of the different layers of the soil, 

 thus rendering the nourishing substances more readily 

 available and causing greater activity in chemical 

 changes. 

 (3.) It freely admits air and heat. 



(4.) It exercises a favourable effect upon the degree of 

 moisture in the soil. Rain water penetrates more 

 readily and to a greater depth, while subsequently, 

 during dry weather, it rises again by capillary 

 attraction. 

 On the other hand the following drawbacks must be 

 mentioned : — 



(1.) On steep slopes loosening the soil may be followed by 

 denudation, as rain water can more easily carry it 

 away. 

 (2.) Frost lifting may occur more frequently. 

 (3.) It may attract injurious insects, such as the cock- 

 chafer, the larva? of which are very destructive to 

 the roots. 

 The degree of loosening, and the depth to which it may 

 reach, depend on the original condition of the soil. Hard 

 or wet soil requires more, naturally loose soil less or no 

 working. 



In some cases the actual process of loosening the soil must 

 be preceded by the removal of an obstructive surface covering, 

 such as woody shrubs, weeds, grass, moss, ferns, heather, 

 raw humus, etc. ; in other cases this is not necessary. The 

 loo.:ening itself can be done in a variety of ways ; l)y means 

 of tools, sucli as the plough, harrow, rake, hoe, or spade; l)y 



