298 QUALITY OF BARLEY GROWN AFTER ROOTS. 

7s. 6d., making with the cost of sowing a total expenditure of 
8s, per acre, 
We thus obtain a net profit of 28s. per acre for the appli- 
cation of 3 cwt. of superphosphate per acre to barley taken 
after roots folded on the land. 
Effect of Sulphate of Potash——To judge of the effect pro- 
duced by a dressing of 1 cwt. per acre of sulphate of potash 
(go per cent.) it is necessary to compare samples C, from land 
which received 3 cwt. superphosphate and 1 cwt. of sulphate 
of phosphate, with samples B, from plots receiving the super- 
phosphate only. It will be seen that in each series the 
starch reached its maximum in the grain which had been 
grown with potash manure, but no consistent effect upon the 
other constituents of the barley can be traced. These results 
accord with the known function of potash in determining the 
formation of carbohydrates. It is, however, somewhat sur- 
prising to find so small a quantity of potash producing 
this effect when the soil had previously been enriched in 
soluble potash by the residue from feeding the roots. The 
increased proportion of starch should make the barleys more 
valuable for brewing, but the ordinary commercial valuation 
does not set these samples at any higher price. 
Effect of Salt—rThe plots from which came the samples 
marked D received 3 cwt. salt per acre in addition to 3 cwt. 
superphosphate ; hence a comparison must be made between 
samples D and B to ascertain the effect of salt. It is seen 
that the salt always causes a deterioration of sample; the 
starch is lowered, the nitrogen is increased, and the propor- 
tion of flinty corns similarly rises. 
These results are in accord with those obtained in 1897 
and 1898; in all the seven cases reported the proportion of 
nitrogen had been increased by the dressings of salt, and in 
most cases other evidence of the deterioration of the samples 
by dressings of salt was to be found. 
Composttion of the barleys as affected by manures :— 
The samples numbered 22-28 are not comparable with the 
others; they are from plots upon the College farm, where 
barley had been grown for five years in succession, the 
manurial treatment having been the same each year. The 
