160 THE WHEAT CULTUEIST. 



wheat would not be very much injured by the freezing 

 and thawing of the soil. 



" Every intelligent farmer knows that when the soil 

 freezes it is expanded ; and as the expansioa must 

 nearly all be upward, plants are sometimes lifted from 

 one to two inches, i.e., the surface of the upper soil is 

 from one to two inches further above the subsoil than 

 it is when it is not frozen. Of course, this expansion 

 lifts the plants with it, and if the roots have struck 

 downward farther than three or four inches, they must 

 be severed between the frozen and unfrozen soil. But 

 in case most of the roots have shot out in nearly a hori- 

 zontal direction, the plants and roots will all rise and 

 settle back bodily, as the soil freezes and thaws, and but 

 very few of the roots will be broken oif. 



" Now, when the soil is "ploughed deep for winter 

 wheat, the roots must necessarily strike deep downward 

 in order to obtain sufficient nourishment, unless the 

 entire soil is filled with vegetable matter and manorial 

 substances for nourishing the young plants. But when 

 the large proportion of vegetable matter and manure 

 are near the surface, the roots all spread out nearly in a 

 horizontal direction, forming a kind of mat or tender 

 sod, which all rises in a body when the earth freezes, 

 without severing any of the roots, except those few that 

 have struck downward beyond the super-soil." 



IMPORTANCE OF SUBSOILINGL 



The hard, impervious stratum beneath the fertile 

 mould needs to be thoroughly pulverized, so that the 

 roots of all kinds of cultivated plants may strike deep 

 and feed on the vast stores of mineral pabulum that 



