47 
A Study of Colorado Wheat 
I have had some difficulty in finding data which show what 
the variations may be in the mineral constituents of wheat straw 
under ordinary conditions. The most of the data I have found has 
been taken from Wolff’s “Aschenanalysen” without any explana¬ 
tions as to what the data represent. The figures given below to 
represent the general analysis of the ash of wheat straw, have been 
taken from Van Slyke’s “Fertilizers and Crops.” 
The methods followed in the determination of the mineral 
constituents of the straw will be given at a future time. It may, 
however, be stated here that we found it impossible to determine 
the phosphorus by direct incineration in the presence of so much 
silica and carbon. 
THE MINERAL CONSTITUENTS OF AIR-DRIED WHEAT STRAW. 
Ca 
Mg 
Fe 
Mn 
K 
Na 
P 
Si 
Per 
Per 
Per 
Per 
Per 
Per 
Per 
Per 
cent 
cent 
cent 
cent 
cent 
cent 
cent 
cent 
General Analysis. 
0.21 
0.08 
0.02 
0.48 
0.05 
0.12 
1.45 
Defiance—■ 
31 July, 1913. 
Nitrogen . 
0.22 
0.08 
0.03 
0.012 
1.81 
0.04 
0.07 
1.54 
Phosphorus .. . 
0.11 
0.03 
0.01 
0.002 
0.99 
0.02 
0.06 
2.08 
Potassium .... 
0.13 
0.03 
0.01 
0.001 
1.09 
0.01 
0.09 
2.19 
Check . 
0.16 
0.05 
0.02 
0.009 
1.20 
Trace 
0.08 
1.94 
Fife— 
31 July, 1913. 
Nitrogen . 
0.21 
0.09 
0.02 
0.002 
1.53 
0.12 
0.12 
1.76 
Phosphorus .. . 
0.14 
0.05 
0.01 
0.002 
1.00 
0.02 
0.06 
2.09 
Potassium . 
0.15 
0.05 
0.02 
0.002 
1.23 
0.01 
0.09 
2.36 
Check . 
0.19 
0.08 
0.02 
0.009 
1.05 
0.02 
0.12 
1.97 
Kubanka— 
6 August, 1914. 
Nitrogen . 
0.16 
0.03 
0.01 
0.003 
0.96 
0.14 
0.03 
2.40 
Phosphorus .. . 
0.11 
0.02 
0.01 
0.002 
0.72 
0.05 
0.02 
2.70 
Potassium . 
0.08 
0.02 
0.01 
0.001 
0.77 
0.09 
0.02 
3.00 
Check . 
0.18 
0.07 
0.01 
Trace 
1.05 
0.09 
0.03 
2.60 
The manganese determinations are given for the purpose of 
showing that this element is uniformly present but the percentages 
are not correct as they represent only that portion of the manganese 
that was carried down as an oxalate with the calcium oxalate. The 
portion of manganese thus carried down varies greatly even when 
only small quantities are present, as in these cases, but the results 
serve perfectly for the purpose for which they are given. 
The amount of sulphur given by Van Slyke is five one- 
hundredths of one percent. 
It appears from the results presented that the mineral constit¬ 
uents of the plant as represented by these straws are decidedly in¬ 
fluenced by the relative food supply furnished by the soil. I am 
aware that this view was held for a long time as almost self- 
evident, but so much stress has been placed of late years upon the 
