IO 
Colorado Experiment Station 
stroyed by reduction, there will still remain enough to counter¬ 
balance, for the one crop, the influence of the available potassium. 
This feature of the yellow-berry problem will be discussed further 
in this bulletin, and the composition and properties of such wheat 
will be treated of fully. 
The experiments planned, consisted of three series with each of 
three varieties of wheat. Each series of experiments had four 
members including a check. The size of the plots was one-tenth of 
an acre. We made other experiments concurrently with these in 
which we used smaller plots. Casual reference may be made to 
these but they form no part of the series presented in this bulletin. 
The soil chosen for these experiments varies some in character, 
but it is as nearly uniform as can ordinarily be obtained. The land 
is quite level and is easily irrigated. We have analyzed this soil, 
represented by samples taken from different portions of the field at 
various times. There are some differences, but whether they are 
great enough, compared with the total amount of the substances 
present, to justify one in giving them further consideration or not 
is a question. Absolute uniformity in areas of the size of the 
aggregate here used, about six acres, is not to be obtained. The 
mechanical and chemical analyses, including mass analyses of both 
the soil and subsoil, are given below. 
There is but little use in discussing the amount of plant food 
present as indicated by the analyses, still it gives us a certain indef¬ 
inite idea of abundance or lack of this food which, in a general way, 
may be of service. The amounts given are calculated for 8,000,000 
pounds of soil, because the soil and subsoil together were taken to a 
depth of two feet. The total amount of potassic oxid present in 
this land taken to this depth is approximately 203,280 pounds, or 
101.6 tons; of phosphoric acid, 16,080 pounds, 8 tons; of nitrogen, 
8,240 pounds, 4% tons. 
MECHANICAL ANALYSES OF THE SOIL AND SUBSOIL. 
Size of Particles. 
Soil 
Subsoil 
Percent 
Percent 
Over 
1 mm. 
. 0.092 
0.112 
From 
1 to 0.5 mm. 
0.456 
From 
0.5 to 0.25 mm. 
. 1.810 
1.122 
From 
0.25 to 0.05 mm. 
. 45.790 
49.883 
From 
0.05 to 0.01 mm. 
. 28.742 
25.514 
From 
0.01 to Clay. 
9.617 
Clay 
by difference. 
3.707 
Moisture and organic matter. 
. 9.890 
9.589 
100.000 
100.000 
