IXFLL'EXCE OF AMMONIA ON QUALITY 113 



There is seen to be little difference in composition between 

 the roots grown with ammonia salts, superphosphate and 

 potash, and those grown solely with farmyard manure. The 

 manuring on each of these plots may be described as a well- 

 balanced manure. When the farmyard manure is enriched by 

 400 Ibs. of ammonia salts, without a corresponding addition of 

 ash constituents, the composition of the roots distinctly alters 

 for the worse. Mangels manured with nitrate of soda are 

 somewhat more watery, and contain a distinctly less propor- 

 tion of sugar than those manured with ammonia salts. 



\Ye have already pointed out that in the case of the 

 mangel/ crop it is the quantity of feeding material produced 

 per acjg, rather than the percentage composition of the roots, 

 which demands the first consideration. In the case now before 

 us the falling percentage of sugar is attended with a great rise 

 in the quantity of sugar per acre, and the inferior percentage 

 composition consequently ceases to be an argument against the 

 manures em ployed. The figures are as follows : 



Sugar. Sugar per Acre. 



We have seen in Table XXXVIII that the use of nitroge- 

 nous manures distinctly increases the percentage of nitrogenous 

 matter in the root. The nitrogenous matter in mangel roots 

 is a mixture of many substances, nitrates, amides and albumin- 

 oids ; we cannot therefore take the total quantity of nitrogen 

 found as representing feeding material. The percentage of 

 albuminoids in the root does however rise by the employment 

 of nitrogenous manures, and as the percentage of sugar at the 

 same time falls, it follows that the albuminoid ratio of the feed- 

 ing constituents in a mangel root differs very much according as 

 nitrogenous manures are, or are not, employed. The use of 

 ammonia salts will always tend to narrow the albuminoid 

 ratio. 



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