REPORT OF THE CHEMIST 163 



SESSIONAL PAPER No. 16 



ON THE CHANGES IN THE COMPOSITION OF ROOTS DURING 



STORAGE. 



There is an impression among many stock feeders of experience that the feeding 

 qualities of ordinary farm roots improve with storage. This opinion, however, is not 

 generally held, and it was, therefore, to ohtain further information regarding possible 

 changes in the composition of roots during storage in a root cellar, that analyses were 

 made from time to time (from October, 1900, to March, 1901) of several varieties from 

 the crop of 1900. The roots examined included three varieties of mangels, two of car- 

 rots, and one each of turnips and sugar beets. About two bushels of each variety were 

 selecte4 — roots of typical size and shape only being taken — and placed in bags which 

 were throughout the investigation kept buried in a large heap of roots in the cellar. 

 By this means the conditions of storage obtained were similar in all respects to those 

 ordinarily prevailing in good root cellars. On March 15, the last date of analysis, the 

 roots remaining were all sound and in good condition. The sample for analysis in 

 each instance consisted of six roots. 



Before discussing the results of the present investigation, however, it may be pro- 

 fitable to consider certain facts regarding this problem that have been recently brought 

 to light by the researches of other investigators. In 1898, Wood showed the nitrates 

 present in the juice of the mangels, as pulled, decreased in amount to the extent, ap- 

 proximately, of one-half by January 15. ' These nitrates, he states, ' are liable to 

 cause derangement in digestion; by January these nitrates have been changed into 

 amides which have some feeding value and are quite harmless.'* The probability is 

 that under systems of manuring as practised in Canada, nitrate of soda or sulphate 

 of ammonia not being extensively used, the proportion of nitrogen in the freshly pulled 

 root present in the form of nitrates is not so large as that in roots from highly ferti- 

 lized fields, as in England. Nevertheless, this discovery is an important one as show- 

 ing the trend of change in certain of the nitrogenous compounds of roots. 



In an exceedingly able and exhaustive paper on this subject, Dr. A. H. J. Miller,! 

 after quoting results obtained by the late Dr. Voelcker, to the effect that stored roots 

 undergo considerable change, chiefly by loss of sugar and allied bodies, and possibly 

 also of nitrogenous compounds, due to a process of slow combustion, gives in detail 

 the data of an interesting series of experiments conducted by himself on mangels grown 

 with and without nitrate of soda at Rothamsted. After tabulating the results 

 from mangels receiving no nitrate, Dr. Miller concludes : ' No essential 

 change (except in total weight, evidently due to loss of water) took place 

 up to the end of March. During the next three months (i.e., till the end 

 of June), however, there was a considerable loss of dry matter, much of 

 which was due to destruction of sugar, whilst about half the cane sugar was inverted.' 

 By June 20, about 14 per cent of the total sugar originally present had disappeared, 

 but the loss in non-nitrogenous matter other than sugar exceeded this amount. The 

 examination of mangels that in addition to other manure had received 550 pounds of 

 nitrate of soda per acre showed ' a regular decrease both of dry matter and of sugar. 

 Even by the end of March the loss of sugar was considerable, and a good deal inverted.' 

 After discussing the probable loss in sugar per acre of roots by storage until the end 

 of June, he says: ' Taking into account the variety of conditions which presumably 

 affect the changes undergone by stored roots, any conclusions drawn from the results 

 can only be given with some reserve. It seems, however, very probable that a consider- 

 able loss of the most important constituent, sugar, and of other constituents, does fre- 

 quently take place. That nitrate of soda increased the loss of sugar, if not of other 

 constituents, seems to be highly probable, since the two lots of roots were kept together 



•Changes in Mangels during storage, T. B. Wood, Journal R.A.S.E., 3rd series, Vol. IX., 

 part III. 



tExperiments at Rothamsted on the changes in the composition of mangels durlnj 

 storage, A. H. Miller, Journal R.A.S.E., 3rd series, Vol. XI., part I. 



16— Hi 



