22 
MANURING EXPERIMENTS WITH PADDY RICE (THIRD YEAR). 
Assimilated 
from 100 parts of 
phosphoric acid 
originally applied. 
°lo 
Relative 
assimilability 
in the two 
first seasons. 
in the 
first season. 
Double Superphosphate 
.. ..28.2 
IOO 
IOO 
Precipitated phosphate 
.. ..32.5 
115.2 
104.0 
Crude Bone Dust.. 
73-0 
60.4 
Steamed Bone Dust .. 
.. .. 19.9 
70.6 
58.6 
Thomas Phosphate 
.. ..20.3 
72.0 
5 6 -9 
Peruvian Guano .. 
50.2 
34-4 
Bone Ash . 
33-7 
27.4 
Phosphorite. 
13-6 
7 -i 
The figures for the relative assimilability most satisfactorily 
coincide with the numbers for the relative increase of the crops. 
The following averages of the two series of results may accord¬ 
ingly be regarded as standards for the calculation of the 
quantities of various phosphates suited for rice under conditions 
similar to ours in respect to soil and climate. 
Relative manurial value 
__A___ 
in 
the first 
in the first 
season 
and second seasons. 
Double Superphosphate. 
IOO 
IOO 
Precipitated Calcic Phosphate 
106 
113 
Crude Bone Dust. 
60 
74 
Steamed Bone Dust . 
.56 
74 
Thomas Phosphate. 
53 
74 
Peruvian Guano . 
34 
54 
Bone Ash. 
‘48 
33 
Phosphorite . 
9 
16 
The two } T ears’ experiments 
have 
shown that among the 
various phosphates experimented on, the precipitated calcic 
phosphate occupies the first rank in each of the two seasons ; 
the first crop assimilated 25.1, the second 7.4% of the phosphoric 
acid applied in this form. Very similar, though a little inferior 
to the fertilizer is the superphosphate with an assimilation-factor of 
24.1% in the first season and 4.1% in the second. Next in order 
of their action, follow the two kinds of bone dust and the Thomas 
