26 
MANURING EXPERIMENTS WITH PADDY RICE (SECOND YEAR). 
Wagner. 
Our results 
with rice. 
Superphosphate . 
. 100 
IOO 
Thomas phosphate 
.5° 
53 
Peruvian guano . 
. 30 
34 
Steamed bone dust 
. 10 
56 
Coprolite powder. 
. 9 
9 11 
In spite of the great differences in the conditions of soil and 
climate as well as the character of the crops in Wagner’s 
experiments and in our own, we find a striking resemblance 
between his results and ours. Indeed, as to the relative value 
of superphosphate, Thomas phosphate, Peruvian guano, and 
phosphorite there is such a close coincidence between the two 
series of experiments as would be satisfactory even if obtained 
from parallel trials made under exactly the same conditions. 
With reference to the steamed hone dust, however, a great 
difference will be noticed between our figures and Wagner’s ; 
while we found, on the irrigated land, the action of the phos¬ 
phoric acid of this fertilizer to amount to as much as 56% of 
that of the phosphoric acid of superphosphate, Wagner 
observed it to be only 9%. In both cases the results are not 
the outcome of a single observation, but Wagner’s experi¬ 
ments were made on two kinds of soil with 5 crops 13 and ours 
are likewise confirmed by the trials with crude bone dust, 
altogether on 12 single plots, as well as by new researches on 
dry land with barley 12 . The effect of bone dust varies ac¬ 
cordingly within wide limits, the dependency of which on the 
conditions of soil, moisture, and climate needs still further 
investigation. 
Hitherto we have taken into consideration only the increase 
of the crop and the assimilability of phosphoric acid on the 
plots supplied with the smaller doses of phosphates. The 
larger doses no longer exerted their full action on the yield, 
11 Powdered phosphorite. 
12 A report on these experiments will be published in one of the next 
bulletins. 
