36 The Colorado Experiment Station 
It is almost fallow ground. The beet field was a cropped field with 
the beets well grown and the ground well shaded. Here we find 
an average of 0.0000975 P er cent of nitric nitrogen not including 
the fallow strip for the depth of from 2 to 6 inches. This is equi¬ 
valent to 7.8 pounds of sodic nitrate in these four inches of soil 
per acre. These examples include our extremes but these are 
small quantities compared with the nitrate content of the first foot 
of soil of Orchard No. 2, 49.5 tons, or with the soil from the 5th to 
the 17th inch inclusive from Orchard No. 1, 6.5 tons per acre foot. 
While the nitric nitrogen in the soil of the College farm is probably 
normally high, it is simply not comparable to the samples of soils 
from these orchards. The Rothamsted experiments showed that 
during a period of from 14 to 15 months nitric acid equivalent to 
553 and 572 pounds of commercial sodic nitrate was formed in the 
first 27 inches of soil per acre. This included the amount removed 
by drainage. This would give us 0.00625 per cent sodic nitrate 
counting the weight of an acre foot of soil as 4,000,000 or 0.00726 
per cent counting it as 3,500,000 pounds. 
The general character of these soils is given by the following 
analyses. 
ANALYSES XXX, XXXI, XXXII AND XXXIII. 
No. 724 
No. 725 
No. 697 
No. 785 
per cent. 
per cent. 
per cent. 
per cent* 
Insoluble ... 
.54.653 
57.068 
j 76.500 
64.820 
Silicic Acid. 
.19.805 
12.754 
5.650 
Sulfuric Acid. 
. 0.047 
0.049 
0.320 
0.810 
Chlorin. 
. 0.032 
0.059 
3.090 
0.890 
Phosphoric Acid. 
. 0.120 
0.127 
0.120 
0.180 
Carbonic Acid. 
. 3.048 
6.312 
3.470 
7.040 
Lime. 
. 6.100 
8.465 
3.490 
7.180 
Magnesia .. 
. 1.355 
1.448 
2.080 
2.190 
Sodic Oxid. 
. 0.290 
0.432 
0.840 
0.840 
Potassic Oxid. 
. 0.872 
0.742 
0.590 
0.690 
Ferric Oxid. 
. 5.601 
3.499 
3.040 
3.110 
Aluminic Oxid. 
. 3.738 
5.397 
4.020 
2.250 
Manganic Oxid (br). 
Moisture. 
. 0.118 
0.026 
1.370 
1.470 
Ignition.. 
. 5.072 
3.887 
1.760 
2.970 
Sum. 
.100.851 
100.265 
100.690 
100.090 
O equiv. to Chlorin..... 
.. 0.007 
0.013 
0.690 
0.200 
100.844 
100.252 
100.000 
99.890 
Total Nitrogen. 
. 0.147 
0.069 
0 080 
0.072 
Humus. 
. 0.426 
0.248 
Samples 724 and 725 represent the soil and subsoil of the Ex¬ 
periment Station plots. The surface soil has a depth of one foot 
and the subsoil was taken to a like depth, so the samples represent 
the first two feet of the plot. Samples 697 and 785 represent soils 
of orchards which have suffered severely from the effects of exces¬ 
sive quantities of nitre. These four soils differ principally in the 
