INFLUENCE OF AMMONIA ON QUALITY 



93 



leaf; where ash constituents are liberally supplied there is, 

 on the contrary, a vigorous production of flowering stems. 

 This difference in the development of the grass considerably 

 affects its chemical composition. The leaf is the part of an 

 immature plant which is richest in nitrogenous matter, the 

 stem is the part poorest in such constituents. The leafy, 

 ill developed herbage, thus always contains a larger percentage 

 of nitrogenous matter. 



The percentages of nitrogenous matter, and of total ash 

 constituents, have been determined in the experimental hay 

 at Rothamsted during many years. The average percentages 

 found in the hay of some of the plots during the first 18 years 

 of the experiments (Watt's Dictionary of Chemistry, 2nd Supple- 

 ment, p. 528) are given in the following table : 



TABLE XXX. 



PERCENTAGE OF NITROGENOUS MATTER AND ASH IN HAY, 



VARIOUSLY MANURED AT ROTHAMSTED, 

 AVERAGE OF EIGHTEEN YEARS, 1856-73. 



\Ye have here the apparently curious fact that the hay 

 grown with ammonia salts, superphosphate, and alkali salts, 

 on plot 9, contains a smaller percentage of nitrogenous matter 

 than the hay of the unmanured plot \vhich has received no 

 ammonia. The cause of this has been already noticed. 

 The cinereals and ammonia salts produce a very large crop, 

 averaging 52 cwts. of hay in the 18 years in question. The 

 nitrogen assimilated from the manure is distributed in this 

 great bulk of produce, so that its proportion in the whole 

 becomes small. The same quantity of ammonia salts applied 



