May, 1921] 
DICKSON — COMPOSITION OF OAT PLANT 
Table 2, The Amounts of Salts in Solution, Electrical Conductivity, and Depression of 
the Freezing Point of the Normal and Modified Solutions 
Solution, Deficient Element 
Given 
Total Soluble Salts in 
Grams per loo Cc. of 
Solution 
Conductivity X lo-s 
Reciprocal Ohms 
Depression of Freezing 
Point in Degrees 
Centigrade 
1916S0I. 
1917 Sol. 
Ave. 
1916 Sol. 
1917S0I. 
Ave. 
1916 Sol. 
1917S0I. 
Ave. 
.110 
.105 
.107 
1-363 
1-507 
1-435 
.050 
.051 
.050 
Mg O.I 
.105 
1-556 
.051 
Ca O.I 
.085 
.070 
.077 
1. 144 
1.058 
I.IOI 
.050 
.050 
.050 
K 0.1 
.109 
.082 
.095 
1-343 
I -45 1 
1-397 
.050 
.051 
.050 
P 0.1 
.098 
.090 
.094 
1-383 
1-305 
1-344 
.050 
.051 
.050 
N 0.1 
.120 
.109 
.114 
1-455 
1.625 
1.540 
.050 
.061 
•055 
development or composition of the plants produced in the respective solu- 
tions. 
General Cultural Methods 
Glazed earthenware jars were used for containers. The plants were 
grown in analyzed quartz sand to which was added the diluted nutritive 
solution. The solution in the culture jars was maintained as nearly as 
possible at 60 percent of the moisture-holding capacity of the sand. 
Pedigreed Swedish select oats, Avena saliva aristata, were used in all 
the experiments. The plants were grown under an open glass house 
exposed to out-of-door conditions from May until August of each year. 
The cultural work from May to August, 1915, and from May to August, 
1916, was carried on under climatic conditions different from those that 
governed the latter part of the work, which differences may in some cases 
explain the differences between the data recorded for the two respective 
periods. In a later part of this paper a comparison will be made of the 
meteorological conditions for the two periods. 
The average grain and straw produced per pot for each year is given 
in table 3. It was not possible to produce large quantities of either grain 
Table 3. The Average Yield of Grain and Straw in Plants Grown in the Normal Solution 
and in Solutions with One Nutrient Element in Each Case Reduced to One Tenth Normal 
No. Det. per 
Year 
Solution, Deficient 
Element Given 
Weight of Grain in 
Grams 
Weight of Straw ip Grams 
1915 Crop 
1916 Crop 
1917 Crop 
1915 Crop 
1916 Crop 
1917 Crop 
4 
Normal 
5.329^=2 
6.986 ± I 
6.362 d=o 
7.o8zt2 
i4-77±2 
28.o8±o 
2 
Mg 0.1 
5.804 ± I 
29.62 ±2 
2 
Ca 0.1 
5.2I2±I 
6.645 ±0 
3.999 ±0 
7.96±2 
i7.2i±3 
20.75±2 
2 
K 0.1 
2.968 =b I 
5.66o±2 
3.268±o 
3-5i±2 
10.22 ±4 
i2.68±o 
2 
P 0.1 
I.I42d=I 
.390 ± I 
.665 ±0 
i.59±i 
.84±i 
2.II d=2 
2 
N 0.1 
i.767±i 
.I20d=I 
.679 dbo 
2.23±I 
.29±o 
2.02 ±0 
or straw in the phosphorus- and nitrogen -deficient solutions. Therefore, 
the samples for analysis from these cultures were rather small, yet with 
special manipulation it was possible to secure results that checked very 
closely. 
