296 QUALITY OF BARLEY GROWN AFTER ROOTS. 

more usual factor of 6:25.* The carbohydrates other than 
starch, which are dissolved by the acid and alkali used in 
determining the crude fibre and have not been directly esti- 
mated, are mostly pentosans. As starch does not admit of 
accurate determination and as ‘crude fibre’ is a purely 
empirical term, the figures are in fair agreement, for Tollens 
has shownf that the pentosans in barley amount to g-10 per 
cent. 
LEiffect of Superphosphate. —In the experiments made 
during 1897 and 1895 upon the same plan dressings of 3 cwt. 
superphosphate had generally given an increased yield of 
corn but not of straw; 5 cwt. of superphosphate had gener- 
ally increased the yield still further, but as these conclusions 
had only been drawn from small plots of 4, acre, it was 
necessary to confirm them by a trial on a larger scale. 
Accordingly the land of the College farm which fell to barley 
in 1899, a field of 174 acres, was equally divided, and one 
half was manured with 3 cwt. superphosphate per acre. The 
crop on each piece was stacked and threshed separately 
with the following results :— 
No. 16, 8°85 acres unmanured gave 49 qrs. head corn, 5 qrs. tail. 
37 L710 Ob) syn) WILD SUPeLpeaveNs 45m umes iy, OF) 
Two fields on Amage Farm, Wye, were treated in the 
same way—half left unmanured, half manured with 5 cwt. per 
acre of superphosphate. The returns were :— 
No. 18, unmanured, 48 bushels per acre. 
yy 19,5 cwt. super, 52 9 rr) 
», 20, unmanured, 46 ,, ia ho 
5» 21, 5 cwt. super, 51 » 13 ess 
These numbers, obtained by experinients upon a com- 
mercial scale, show that a dressing of 3 to 5 cwt. of super- 
phosphate will give an increase of about 5 bushels to the 
acre, an increase that will pay for the application of the 
manure, irrespective of any improvement that may have 
been effected in the quality. 
In order to judge of the effect of superphosphate on the 
composition of the grain, we must compare in the table 
above the samples marked B, which have been grown on 

* See Osborne, J., Am. Ch. Soc. XVII. (1895), 539, and Ritthausen, Landw. 
Ver. Stat. 47 (1896), 391. 
+ Tollens, J. f. Landw. 1897, 106. Cross and Bevan, Berichte, 1894, 27, 1064. 
