July 28, X923 
Efficiency of Phosphatic Fertilizer 
185 
The average values 5 given in Table VII indicate the varying degree 
to which the different phosphates were affected by liming. Acid phos¬ 
phate, basic slag, and double superphosphate were relatively little 
affected by liming, while bone meal lost about 40 per cent of its effi¬ 
ciency and floats lost approximately 75 per cent. This is in accord with 
the results obtained by Prianischinikov ( 22 ) in sand cultures. While 
the average values probably indicate the average of the results that might 
be secured on a large number of different soils, they obviously do not 
permit of the prediction of the effect of lime on phosphates in any par¬ 
ticular soil. 
It was desirable to know whether the time elapsing between the appli¬ 
cation of the lime and the application of the phosphate influenced the 
degree to which lime depressed the efficiency, and likewise whether the 
quantity of lime applied had any appreciable influence when sufficient 
lime was already present to satisfy the lime requirement of the soil. 
An experiment was therefore conducted to gain such information, a soil 
in which lime had markedly affected the efficiency of bone meal being 
used for the purpose. 
Experiment IX was conducted in the same manner as those previously 
described. Each pot contained 20.5 kgm. of soil No. 1524 maintained 
at a water content of 29 per cent of the dry weight. The basic fertiliza¬ 
tion consisted of 4.2 gm. of sodium nitrate, 3 gm. of ammonium sulphate, 
and 4 gm. of potassium sulphate per pot. Twenty plants per pot were 
grown for a period of 43 days. Two different quantities of lime were 
tried. One series of pots received the lime six weeks before either planting 
was done, or phosphates were applied. Another series received the two 
quantities of lime the day before the phosphates were applied. Acid 
phosphate and bone meal were both applied immediately before planting 
was done. Table VIII gives the results of the experiment. 
Table VIII .—Effect of quantity of lime and the time it was applied on the efficiency of 
bone meal in Experiment IX 
Time lime was applied. 
Lime 
(CaO) 
applied 
per 
pot. 
Phosphate 
applied 
immediately 
before planting. 
Phos¬ 
phoric 
acid 
per 
pot. 
Oven-dry yield of 
individual pots. 
Aver¬ 
age 
oven- 
dry 
yield. 
Relative 
efficiency 
of bone 
meal and 
acid phos¬ 
phate. 
(Add 
phos¬ 
phate 
applied 
6 weeks 
before 
planting 
to soil 
with 
21.06 gm. 
CaO=» 
zoo.) 
Gin. 
Gm. 
Gm. 
Six weeks before planting. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Immediately before planting... 
Do. 
Do. 
Do. 
21.06 
21.06 
21.06 
21.06 
21.06 
21.06 
42.12 
42.12 
21.06 
21.06 
42.12 
42.12 
No phosphate... 
Acid phosphate. 
do. 
do. 
do. 
Bone meal. 
No phosphate... 
Bone meal. 
No phosphate... 
.30 
. 60 
1.00 
2.00 
1. 25 
1. 25 
Bone meal. i. 25 
No phosphate. 
Bone meal. j. 25 
2. 5 
11.9 
22.1 
27. 7 
4 i- 5 
16.3 
3.0 
5- S 
4.4 
II. 3 
2.8 
4 - 9 
Gm. 
3.4 
11.4 
17. 7 
29.4 
4a 6 
14- S 
3- 1 
4. 1 
4- 9 
15- 2 
4-3 
5.8 
Gm. 
3-6 
Gm. 
3- 2 
11. S 
11. 6 
100 
153 
18.4 
100 
27. 6 
28. 2 
100 
46.8 
430 
100 
13. 2 
14. 7 
34 
3-3 
3 - 1 
4. 6 
4 * 7 
5 
5-5 
4.9 
14. 2 
13.6 
26 
39 
3 . 7 
4.4 
5 .o 
4 
s The few results secured with soil No. 213 were not considered when the average values were calculated 
in order that the latter might be comparable for all the phosphates. 
