July is, 1921 
Assimilation of Nutrient Salts by Corn 
567 
Experiment IX.—The roots divided among three solutions. Various 
combinations of solutions compared. 
It is quite evident from a comparison of the results of the preceding 
experiments that the depressions in growth and absorption were roughly 
proportional to the incompleteness of the solutions afforded the roots. 
This is further demonstrated in the present experiment where solutions 
lacking in different numbers of nutrients are directly compared. The 
results are given in Tables XVI and XVII. 
SUMMARY OF EXPERIMENTAL RESULTS 
The important experimental data of all the tests are gathered together 
in Table XVIII. Since only nitrogen, phosphorus, and potassium were 
varied in these tests (calcium, magnesium, sodium, iron, sulphate, and 
chlorid being present in all the solutions), the different nutrient solutions 
are designated in Table XVIII by their content of nitrogen, phosphorus, 
and potassium. NP, for example, refers to the solution lacking potas¬ 
sium, and NPK stands for the complete solution, while O represents the 
solution lacking the three elements. The different combinations of solu¬ 
tions tested are arranged in Table XVIII with the idea of facilitating 
comparisons. 
Tabus XVIII .—Summary of results of experiments I to IX 
Experiment 
No. 
I 
I 
I 
II 
III 
III 
III 
IV 
IV 
IV 
IX 
V 
IX 
VI 
VI 
IX 
VII 
VII 
VIII 
Solution. 
A flasks. 
NPK. 
NPK. 
NPK. 
NPK., 
PK... 
PK... 
NP.... 
PK... 
NP.... 
NK... 
NPK.. 
PK... 
NK... 
NP.... 
NP.... 
NK... 
PK... 
NP.... 
N. 
B flasks. C flasks. 
N. 
P. 
K. 
O. 
NK.... 
NP. 
NK.... 
N. 
K. 
P. 
PK... . 
NK.... 
PK.... 
PK... . 
NK.... 
P. 
N. 
K. 
P. 
NP. 
NP. 
N.. 
K. . 
P... 
N. 
P... 
P... 
K. . 
Weight per root. 
A flasks. B flasks. C flasks 
Gin. 
O. 0284 
. 0289 
.0302 
• °455 
. 022 
. 0196 
. 0278 
. 0228 
.0303 
•030S 
.0293 
. 0298 
•0333 
•035 
. 0362 
. 0286 
.0238 
. 0234 
•0373 
Gm. 
O. 0262 
•0193 
. 0205 
. 0267 
•0305 
. 0288 
• 02 59 
. 0301 
.0199 
. 0222 
• ° 2I 5 
• 035 2 
.0376 
. 0218 
.0368 
.0231 
.0311 
. 0308 
.0258 
Gm. 
O. 029 
.0384 
.0309 
. 0212 
. 0232 
. 0248 
. 021 
. 0188 
. 0272 
Percentage of total roots 
by weight. 
A flasks. B flasks. C flasks, 
52.0 
6r. o 
58-3 
62. 7 
42-5 
38-9 
52. 6 
42.5 
61. 4 
56.3 
38.3 
29-3 
36.6 
44- 2 
36.9 
37-9 
32.0 
46. 6 
42.3 
48. o 
39- 0 
4i. 7 
37-4 
57*5 
61. 2 
47-4 
57- 5 
38.6 
43-7 
25- 5 
34-3 
2 9- 3 
27.9 
39- 0 
28. 4 
39-8 
26.8 
27.7 
36.1 
36.6 
34.1 
27.9 
24. 2 
33-7 
28. 2 
26.6 
30. 1 
j 
