Various viiosUhatIc manures on upland soiU. 
»9 
In spite of these differences, the results obtained with the large 
doses coincide in their main features with these found with the 
small ones, and they would show a still closer resemblance with 
the latter, had we based the calculation not on the results with the 
superphosphate but on those obtained with another fertilizer 
(steamed bone dust). The superphosphate shows a somewhat 
peculiar department in our soil; the larger its doses, the more is 
left unconsumed by the first crop and the more of its phosphoric 
acid combines with copious sesquioxides of the soil, in which 
form it is less easily dissolved and consumed by the roots. 
Concerning the manurial value of the various phosphates, 
particular importance must be attached to the proportion of phos¬ 
phoric acid consumed. We therefore append to this paper a 
diagram, where the co-ordinates show the rate of the phosphoric 
acid consumed from ioo grams in the manure, and the abscissa is 
marked with the time of the development of each crop in months.* 
In this place we may take into consideration the figures which 
show how much phosphoric acid, percent of the quantity applied, 
was taken up by each crop. 
A. Percentage of Phosphoric Acid Consumed by 
Each Single Crop. 
Length of action of the phosphates, 
months. 
7 
3 
IO 
3 
Kind of crops. 
ist crop. 
2nd crop. 
3rd crop. 
4th crop. 
Buck- 
Barley. 
Millet. 
Wheat. 
Wheat. 
Double superphosphate . 
21.5 
10.8 
7.2 
0.8 
Steamed bone dust . 
16.6 
7-3 
7.6 
0.1 
Precipitated calcium phosphate 
13-8 
8-3 
8.7 
0.7 
Crude bone dust . 
12.4 
10.7 
22.4 
2.9 
Raw crushed bones. 
12.6 
9.8 
26.5 
6.3 
Thomas phosphate . 
131 
3 * 
S-i 
0.2 
Bone ash . 
5 '° 
34 
8.2 
1.0 
* The table B on the next page contains all data required the construction of this 
diagram. 
