MANURES AND FERTILIZERS. 65 
produced an increase of crop in 46 out of 45 
trials; and (2) in no case has the increase in 
crop been sufficient to pay cost of fertilizer.” * 
This work is supplemented by further work 
along the same line.; ‘Twenty-one separate 
experiments were made on soils varying widely 
in character and located in different parts of 
the State, and extending over at least six years. 
Asaresult of this work Director Thorne con- 
cludes: 
*‘At present prices of cereal crops and of fertilizing ma- 
terials, respectively, the profitable production of corn, wheat 
and oats upon chemical or commercial fertilizers, or upon 
barn-yard manure, if its cost be proportionate to that of the 
chemical constituents of fertility found in commercial fer- 
tilizers, is a hopeless undertaking, unless these crops be 
grown in a systematic rotation with clover or a similar 
nitrogen-storing crop; and the poorer the soil in natural fer- 
tility the smaller the probability of profitable crop produc- 
tion by means of artificial fertilizers.” 
At the Kentucky station, on land rich in 
phosphoric acid, a mixture of muriate of potash 
and nitrate of soda in the proportion of one 
part of the former to two of the latter gave the 
best yields of grain, viz.: an increase of 39 
bushels per acre over where no fertilizer was 
apphed. Combinations of nitrogen and_ phos- 
phoric acid, or single applications of either, 
gave practically a less yield than where no 
* Ohio agricultural experiment station, Bulletin 3, Vol. V, 
March, 1892, 
t Ibid., Bulletin 53, March 1894. 
5 
