Periodical Literature. 79 



prove physical conditions may be more widely employed. The 

 even on the food materials is accentuated, its mechanical con- 

 ditions having" a bearing on the decomposition, the distribution 

 and especially the leaching of the same. The size of the volume 

 of the interstices in the soil and its granular structure are useful 

 measures of the soil quality. Favorable conditions for the pre- 

 serving of granular structure in the forest are the swaying of 

 trees, work of the animal world, cover of foliage, litter and 

 humus, protection against pattering raindrops by crowns. In 

 the forest this works in the same sense as manuring in the fields. 

 As means of improving soil structure, addition of lime, humus, 

 and soil work may be employed. Water supply is the most im- 

 portant need ; regulation of water contents, prevention of rapid 

 drainage, of evaporation from dry soils and in dry seasons, pro- 

 motion of penetration especially of gentle rains, as well as proper 

 limitation of water supplies can be secured by correct and timely 

 soil work. 



In light sands avoid deep soil culture, it is either not neces- 

 sary or is harmful by promoting the leaching of food materials. 

 Depth to which soil work is to be done depends on the object 

 to be attained. It is most desirable to work the soil over often : 

 it needs time to secure the benefits of the work. In seed cuttings 

 the preparation of a seed bed by the repeated use of the Danish 

 roller-harrow is recommended, which costs $1.20 per acre and 

 saves elsewhere, making a seed bed in which every seed comes 

 to germination. Also in clearings followed by planting this 

 working of the soil pays, promoting proper humification and 

 making undesirable soils covers of huckle-berries, etc., innocuous, 

 and mixing the raw humus with mineral soil. 



Hessischer Forstverein. Allegemeine Forst- und Jagdzeitung, 1908, p. 

 406-407. 



The Northern States and Canada abound 

 Making in "bogs" or "swamps," which eventually 



"Swamps" will form an important area for farm and 



Available. forest use. Indeed, for Canada, which in 



this respect is probably more generously en- 

 dowed than the States, the problem of making the extensive bog 

 areas more useful is probably to be solved in the not far distant 

 future. 



