190 



TJie Roots of the Wheat Plant. 



inately tends to a more equable pulverization, and induces the 

 formation of a loamy soil by a gradual admixture of vegetable 

 matter. Farm-yard manure under furrow in such soils, unless 

 very rotten, sometimes aggravates the evil of lifting, as its de- 

 composition takes place but slowly, and straws of long dung are 

 irregular conducting media for water and ice in the soil : it is 

 for this, among other reasons, that direct manuring for wheat is 

 not at all in favour certainly in the midland counties. 



Expansion takes place in some of the stiff argillaceous lands of 

 the lias and Oxford clays, in which much rain acts not by causing 

 crumbling and lifting, but the enlarging of the plastic mass, 

 which is compressed so tightly around the roots as to deprive 

 these organs of free power of growth and action. This plastic 

 element is very injurious to wheat from the comparative slowness 

 with which chemical decomposition proceeds, as it does not 

 readily let in either air or light, and besides it is unusually cold, 

 as all land must be that so resolutely retains water. Here drain- 

 ing, clay-burning, dressing with town refuse, as ashes and the 

 like, judicious cropping, the use of long dung, and indeed what- 

 ever contributes to the disintegration of its present texture, and 

 admixture with other substances is of advantage. Under these 

 circumstances of soil one can understand how it is that the farmer 

 cannot always " get upon" his land — for in some seasons the 

 plough would turn up clods only to be unbaked bricks, at others 

 the whole would be a tenacious paste. On such soils again one 

 does not wonder at the foxhunter calling it a " stiff country," or 



Diagram 10.— Sbowlng the effects of the cracking of soil from drought. 



