WHY RYE MAY FLOURISH AND NOT WHEAT. 115 



part of its transverse section, one-third less nutritive matter 

 than before. The reason is, that by tlie addition of sand 

 the food-affording surface of the other constituent parts 

 of the soil is enlarged, and on this everything depends as 

 regards the power of the soil to give up to plants the food 

 contained in it. 



A soil on which rye thrives well often proves unsuitcd 

 for the profitable cultivation of wheat, though both plants 

 take from the soil exactly the same constituents. 



It is clear that the failure of wheat on such a soil arises 

 from this cause, that the wheat plants, within the allotted 

 period of then- existence, do not find nutriment enough 

 for their full developement in the food-supplying soil 

 about their roots, wdiilst the quantity supplied is ample for 

 the rye plants. 



jSTow chemical analysis proves that such a rye soil alto- 

 gether contains, to a depth of 5 to 10 inches, fifty — nay, a 

 hundred times more of the food-elements of the wheat 

 plant than would be required for an abundant crop of 

 wheat ; and yet, in spite of this superabundance, the field 

 will afibrd no remunerative crop to the agriculturist. 



If we compare the quantities of phosphoric acid and 

 potash dra^vn from an area of 2 J acres (hectare), by an 

 average wheat crop (2000 kilogrammes = 4400 lbs. of 

 grain, and 5000 kilogrammes = 11000 lbs. of straw) and 

 a rye crop (1600 kilogrammes = 3520 lbs. of grain and 

 3800 kilogrammes =8360 lbs. of sti-aw), avc find tliat the 

 two crops severally received from the soil — 



I 2 



