48 
Journal of Agricultural Research 
Vol. XXIV, No. I 
Tabl^ IV. —Rate of absorption of plant foods per hour when wheat seedlings werefeeding 
fractional parts of day 
[From Table II] 
Hours per day. 
Rate of absorption per hour. 
N 
K2O 
P2O5 
I. 
Gm. 
0. 00112 
.00126 
. 00087 
. 00128 
. OOI14 
.00108 
. 00066 
Gm. 
0. 00520 
. 00364 
.00262 
.00257 
. 00203 
.00128 
. 00090 
Gm. 
0. 00140 
.00165 
.00105 
. 00090 
.00078 
.00053 
.00032 
2 .. 
6. 
8. 
12. 
24. 
Tabl® V. —Rate of absorption of plant food per day when wheat seedlings were feeding 
for long periods 
[From Table III] 
Days in solution. 
2 .. 
5 “ 
8 .. 
II 
14 
^7 
Rate of absorption per day. 
N 
K2O 
P2O0 
Gm. 
Gm. 
Gm. 
0. 0285 
0. 02705 
0. CO935 
• 0213 
. 02144 
. 007 
• 01785 
. 01846 
.00516 
. 01667 
• 01579 
. 00521 
. 0126 
. 01249 
. 00363 
. O1219 
.01157 
.00612 
DEMAND OF WHEAT PLANTS GROWN FOR AN INITIAL PERIOD IN A 
FULL NUTRIENT SOLUTION AND SUBSEQUENTLY STARVED 
The second of the two experiments described above was made in an effort 
to measure the demands for plant food that might be developed in plants 
that had been grown in distilled water and had never had any food 
supply except that contained in the seed. It was thought probable that 
other results might be obtained if the plants were first fed heavily, then 
allowed to fast, and the demand brought about by this fast measured in 
a second feeding period, A separate set was started, and when the 
plumules had reached a length of about i cm. all the culture pans were 
placed in a full nutrient solution of a concentration of loo parts per 
million each nitrogen (N), potash (KgO), and phosphoric acid (P2O5) and 
allowed to remain in this solution with frequent changes of solution for 
seven days. . All vrere then placed in distilled water and allowed to stand 
seven days or more, when No. 4 was again placed in the nutrient solution. 
After one more day No. 3 was placed in the nutrient solution, and after 
another day No. 2 was put in the nutrient solution. After one more 
day all four sets were taken down for analysis. In this way, the plants 
were all given plenty of food for the first period, then allowed to fast and 
to develop an appetite during the second period, which was measured 
in the third period. This is shown in Table VI. 
