2.32 



THE RYEGRASS CROP. 



to the turnip crop, and discussed at page 327, vol. i., 

 where it is shown that it is possible for the smaller crop 

 or bulk of produce to contain more nutritive matter than 

 the larger, and thus to be actually the more valuable 

 crop of the two. 



The composition of the ash, or mineral constituents of 

 the plant, is as follows : 



The only point for remark in reference to the inorganic 

 constituents of the ryegrass is the large proportions of 

 silica it requires to carry on its growth. About three- 

 fifths of the whole of the mineral matters are composed of 

 silica. Therefore, taking a medium crop under the irri- 

 gation system of 50 tons to the acre, about 12 cwts. of 

 silica in a Soluble condition would be abstracted from the 

 soil by the growing crop, in addition to the potash and 

 phosphoric acid. 



Surely, with these mineral requirements, ryegrass ought 

 neither to succeed nor precede a straw crop ; and yet, in 

 common practice, we too generally see it doing both. 



1 and - Way and Ogston, Roy. A<jri. Soc. Jour., vol. ix. p. 144. 

 3 R. D. Thomson, researches on Food of Animals, p. 80. 



