Apr. 16,1917 
Absorption of Nutrients 
77 
Table V. —Nitrogen and phosphoric acid absorbed by corn in Experiment II 
Flask No. 
Nitrogen 
(N) in dry 
stalks and 
leaves. 
Nitrogen (N) in dry 
roots. 
Nitrogen 
(N) ab¬ 
sorbed by 
8 plants. 
Nitrogen 
(N) ab¬ 
sorbed per 
gram of 
roots. 
Phos¬ 
phoric 
acid 
(P2O5) in 
dry stalks 
and 
leaves. 
A-flasks. 
B-flasks. 
1-16 
17-32 
33 - 4 * 
Per cent. 
1. OO 
3-66 
3 - 57 
Per cent. 
0. 79 
1. 48 
2. 46 
Per cent. 
0. 79 
2. 72 
2. 46 
Gm. 
Gm. 
Per cent. 
I. 80 
T. 28 
I. 26 
0.6022 
• 7973 
O. 310 
. 210 
The partial-nitrogen plants made noticeably less growth than the 
normal plants, had 23 per cent greater ratio of roots to tops, absorbed 
0.76 of the normal amount of nitrogen, and absorbed 1.48 times as much 
nitrogen per gram of roots as the normal plants. These figures agree 
remarkably well with those obtained in the previous experiment with 
rice. 
EXPERIMENT III.—rice WITH HALF THE ROOTS IN NITROGEN-FREE 
SOLUTION 
EFFECT OF INCREASING CONCENTRATION OF NITROGEN 
A test was conducted comparing the ordinary neutral solution with 
one containing twice the amount of nitrogen, to make sure the previous 
results were not influenced by a scarcity of nitrogen and to observe the 
effect on absorption of increasing the nitrogen. 
The double-nitrogen solution was the same as the complete solution, 
except that the quantities of both potassium nitrate and sodium nitrate 
were doubled. Ferric citrate was used as the source of iron. The plants 
without nitrogen were grown in 200-c. c. flasks for 40 days; all others were 
grown in 200-c. c. flasks for 18 days, and in 500-c. c. flasks for the last 
22 days. Eight flasks were taken as a unit and the units duplicated for 
each treatment. The solutions were changed eight times during the 
experiment. Experimental data are given in Tables VI and VII. 
Table VI .—Growth of rice in Experiment III 
Nutrient solution. 
Flask 
No. 
Weight of stalks 
and leaves. 
Number of 
roots. 
Average oven- 
dry weight 
of roots. 
Ratio 
of 
roots 
to 
tops. 
A-flasks. 
B-flasks. 
1 
Green. 
Oven- 
dry. 
Av¬ 
erage 
oven- 
dry. 
A- 
flasks. 
B- 
flasks. 
A- 
flasks. 
B- 
flasks. 
Nitrogen-free. 
Do. 
Do. 
Complete. 
Complete double 
nitrogen. 
Nitrogen-free. 
Complete. 
fComplete double 
\ nitrogen. 
Complete. 
Complete double 
nitrogen. 
f 1-8 
\ 9-16 
/17-24 
\25-32 
(33~4o 
I41-48 
J49-56 
I57-64 
J65-73 
l 73 - 8 o 
Gm. 
1-63 
1. 77 
91.38 
89.99 
93 - 2S 
93-30 
114. 82 
129- 95 
145 - 35 
121.47 
Gm. 
0.45 
•49 
12. 53 
12. 67 
12. 40 
12- 98 
IS-18 
17 - 45 
19 - 54 
16. 45 
Gm. 
} 0.47 
>12. 60 
>12. 69 
>16.32 
>l8. OO 
/ Si 
\ 56 
( 205 
l 230 
/ 209 
\ 210 
/ 242 
1 289 
/ 280 
l 266 
33 
44 
227 
225 
213 
204 
237 
245 
274 
267 
Gm, 
} 0.14 
> 1.69 
| 1.60 
> 2. 09 
} 2. 25 
Gm. 
0.12 
2. 00 
x. 86 
1. 84 
2.13 
0. 553 
• 293 
•273 
. 241 
•243 
