5°8 
Journal of Agricultural Research 
VoL VII, No. 12 
Table III .—Comparative weights of rice plants grown in acid, neutral, and alkaline 
solutions with 0.002 gm. of iron per liter from ferrous sulphate or ferric citrate 
in 
M 
3 
w 
1J 
•s 
4 
•s . 
Average 
oven-dry 
weight of— 
Composition of stalks and leaves. 
Nutrient 
solution. 
Source of iron. 
6 
z 
to 
m 
& 
£ 
4 l 
l 
0 
73 
8 M 
> 
0 
Oven-dry w 
roots. 
Stalks and 
leaves. 
Whole plant. 
1 
P 
8 
Silica (SiOa). 
X 
O 
5 
a> 
■ a 
Magnesia 
(MgO). 
Phospho r i c 
acid (P2O5). 
1 
I 
t -4 
fFerrous 1 
\ sulphate! 
fFer ric I 
\ citrate.. J 
fFerrous 1 
\ sulphate] 
fFerric f 
\ citrate.. | 
fFerrous 1 
\ sulphate] 
fFer r i c [ 
\ citrate.. j 
1-6 
Gm. 
38.44 
27 . 22 
Gm. 
4 - 57 
A. AO 
Gm. 
I. 12 
Gm. 
Gm. 
P. Ct. 
P. ct. 
P. CL P. ct. 
P. ct. 
P. Ct. 
Acid.... 
7-12 
I. 07 
I -03 
I. 21 
13-18 
19-24 
25-30 
31-36 
37-42 
43-48 
49-54 
S 5 - 6 o 
61-66 
32.604.05 
46. 02 5.13 
40. 24I4. 63 
43 - 64 5 - !3 
25 - 25:2- 99 
29. 67I3. 48 
26. 66J3. 20 
38. I4|4. 45 
3 i- 78 : 3 - 79 
38. 78)4. 45 
13. 201. 76 
21. 05I2. 60 
19. 13 2. 34 
33 - 3 ° 3 - 98 
39. 72 4. 78 
33. 644. 09 
4-37 
5-44 
13. 90 
O. 26 
0. 74 
I. 18 
2 . 03 
0. 044 
Do. . 
I. 14 
I. 26 
•74 
■ 83 
• 76 
1. 06 
4.96 
6. 16 
14.41 
• 13 
• 75 
I. 18 
I.97 
• 039 
Neutral. . 
3. 22 
3 - 99 
14. I9 
.28 
•79 
I.44 
2. 03 
. 028 
Do. . 
.92 
1. 02 
•70 
1. 07 
.85 
1. 25 
. 67-72 
73-78 
79-84 
85-90 
91-96 
97-102 
103-108 
4-23 
5-23 
14 . 23 
. 22 
.78 
I- 15 
I.94 
. 024 
Alkaline 
2. 23 
3- 10 
13.64 
•39 
.96 
I. 23 
2. 17 
. 026 
Do. . 
i *43 
4. 28 
5- 68 
14. 22 
. 22 
• 87 
I. 16 
2. 02 
. 021 
The color of the plants during growth was as follows: After 8 days 
growth plants 1 to 18 were a good green, and all others were strongly 
chlorotic; after 15 days growth plants 1 to 36 were a good green, 91 to 108 
were slightly chlorotic, 55 to 72 were chlorotic, 73 to 90 and 37 to 54 were 
strongly chlorotic; after 23 days growth plants 1 to 36 were dark green, 
91 to 108 and 55 to 72 were light green, 37 to 54 were a lighter green, and 
73 to 90 were chlorotic. 
In this experiment there was a greater difference in growth between 
the acid and neutral solutions with 0.002 gm. of iron per liter from ferrous 
sulphate than in the preceding experiment, probably due to the different 
method of preparing the solutions. The residual solutions not only con¬ 
tained less soluble iron than the freshly prepared solutions, but the pre¬ 
cipitate already formed in the residual solutions probably affected the 
rate at which the iron in the freshly prepared solutions became insoluble. 
RESULTS OF PRELIMINARY EXPERIMENTS 
The three preliminary experiments showed that the effect of the reac¬ 
tion of the solution on growth and assimilation of iron depended some¬ 
what on the quantity of iron added. With 0.002 gm. of iron per liter 
from ferrous sulphate, growth was greatest in the acid solution, but with 
0.008 gm. of iron per liter, growth was greatest in the neutral solution. 
