THG JOURNAL 



OF 



Yfie department of Mgricufture 



OF LJBJ^ARY 



New vork 

 VICTORIA. b^jr^'' .1^ 



Vol. X. Papt 4. loth April, 1912. 



WHEAT AND ITS CULTIVATIOX. 



{Continued from ptige 191.) 

 A. E. Y. Richardson, M.A., B.Sc. {Agric.) Agricidtiiral Superintendent. 

 III._FOOD REQUIREMENTS AND CHEMICAL COMPOSITION. 



The manner in which the young wlieat plant builds up its tissues from 

 simple inorganic m.aterials has been described, and it now remains to con- 

 sider from an analytical point of view the composition of the grain and 

 straw elaborated by the plant's activity. We need not enter at this stage 

 into a discussion of the effect of environment on the chemical composition 

 of the product or on the milling quality of the kernel. It is sufficient to 

 note that the climate, the nature of the soil, the mode of fertilization, and 

 even the cultivation of the soil are all important factors in influencing the 

 quality and character of the grain. It has already been remarked that the 

 food of plants consists of 10 essential elements, namely, carbon, hydrogen, 

 oxygen, nitrogen, sulphur, phosphorus, iron, magnesium, potassium and 

 calcium ; and that three other elements, though invariably present in the 

 ash, are not regarded as essential to plant life. 



Now of these essential elements seven are obtained from the soil, whilst 

 three, carbon, hydrogen and oxygen are obtained either from air or from 

 water. One of the most interesting and astonishing facts in agricultural 

 science is that no less than 95 per cent, of the total dry-matter of the plant 

 i= obtained not from the soil at all. 



The imp >rtance of this fact is m.ore evident when we consider that, 

 whilst the air contains practically an inexhaustible supply of carbon, con- 

 stantly replenished by the vital activity of animals and by the processes of 



3831. H 



