MANURING EXPERIMENTS WITH PADDY RICE (SECOND YEAR). 
23 
harvest on the basis of the produce of hulled grain, we may 
now calculate, firstly, the increase of this product over the 
plot without phosphatic manure caused by xo kilogrms of 
phosphoric acid in the case of the smaller doses of this nu¬ 
trient, and secondly, the relations of these surplus yields to 
that effected by the phosphoric acid of superphosphate : 
Superphosphate 
Increase of hulled 
grain for 10 kilo¬ 
grms. of phosphoric 
acid. 
kilogrms. 
. 5 o 8 
Relations of the 
increase, phos¬ 
phoric acid of 
superphosphate 
= 100 
100 
Sodium phosphate 
. 2 55 
50.2 
Precipitated calcium phosphate ...544 
107.1 
Peruvian guano 
.169 
33-3 
Thomas phosphate 
.248 
48.8 
Steamed bone dust 
.269 
53 '° 
Crude bone dust ... 
.30+ 
00 
CTï 
10 
Bone ash . 
.148 
29.1 
Phosphorite . 
.60 
ii. 8 
Before entering into a discussion of these results we may 
consider the proportions of phosphoric acid consumed by the 
plants from the soil and manure, as found by the chemical 
analysis. 
