4io 
Journal of Agricultural Research 
Vol. VII, No. 9 
total phosphoric-acid content as the concentration of the sodium sulphate 
increases. This effect is in evidence throughout the range of sodium- 
sulphate concentrations employed. 
■Table II .—Effect of sodium sulphate on the weight and composition of wheat seedlings 
Cul¬ 
ture 
Parts per million of so¬ 
dium sulphate add¬ 
ed to nutrient solu¬ 
tion. 
Green 
weight 
of IOO 
plants. 
Dry 
weight 
of IOO 
plants. 
Weight of element in 
100 plants. 
Percentage of dry- 
weight of plants. 
No. 
N. 
K2O. 
P2O5. 
N. 
K2O. 
P2O5. 
I 
0. 
Gm. 
63. I 
Gm . 
5 - 85 
Gm. 
O. 206 
Gm. 
O. 369 
Gm. 
O. 141 
3 - 5 
6-3 
2. 4 
2 
5 °.. 
67. 0 
6. 07 
. 178 
• 367 
•ISO 
2.9 
6. 0 
2. 4 
3 
100. 
69.4 
6. 23 
. 163 
• 367 
. 140 
2. 6 
5*9 
2. 2 
4 
200. 
66.6 
5 * 75 
.181 
• 385 
• 133 
3 - 1 
6. 7 
2*3 
5 
300 . 
67. 2 
6. 08 
• J 94 
• 370 
• 125 
3-2 
6. 1 
2. 1 
6 
400. 
65 -5 
6.13 
. 184 
• 367 
. 120 
3 *o 
6. 0 
2. 0 
7 
s°° . 
62. 5 
5-75 
. 194 
• 31 * 
. 120 
3*4 
5*4 
2.1 
8 
1,000. 
59 -o 
5 * 75 
. 176 
. 248 
. I06 
3 *i 
4-3 
1.8 
SODIUM CARBONATE 
The data obtained with culture solutions containing sodium carbonate 
are presented in Table III. The absolute quantities of potash, nitrogen, 
and phosphoric acid found in ioo seedlings are plotted in figure 3 against 
Fig. 3.—Graphs showing the effect of sodium carbonate on the nitrogen, potash, and phosphoric-acid con¬ 
tent of wheat seedlings. First series. 
the sodium-carbonate concentration. The results show a marked 
reduction in the amount of potash and phosphoric acid in the seedlings 
as the concentration of the sodium carbonate increases, the total potash 
or phosphoric-acid content of 100 wheat plants grown in the presence of 
1,000 p. p. m. of sodium carbonate being only one-third that of the 
plants grown in the control solutions. The total nitrogen content of 
the wheat plants is also slightly decreased. 
