A Study of Colorado Wheat 
21 
The total nitrogen is slightly higher in 1915 than in 1913. 
While this is subject to variation, due to the difficulties of sam¬ 
pling, it is true of so many samples that we may perhaps give it 
some weight even though the differences are very small. The soil 
conditions vary less in the two seasons than the ’weather conditions 
led me to expect. 
THE EFFECTS OF INDIVIDUAL FERTILIZERS UPON THE GROWTH 
OF THE PLANTS 
In Part I (Bulletin 208), p. 31, et seq., we stated that we could 
not discern any differences in the growth and ripening of the plants 
on the various plots, except on those that had received a dressing of 
sodic nitrate. The smallest amount of this salt applied, equal to 40 
pounds of nitrogen, sufficed to produce a very marked difference in 
the color, growth, and tendency of the plants to lodge. The ten¬ 
dency to lodge varied considerably in the different varieties of 
wheat used. The Defiance seemed most susceptible. We would not 
be justified in asserting that 40 pounds of nitrogen per acre pro¬ 
duced as serious results as 120 pounds, still it was enough to cause 
the plants to show its effects just as sharply as the 120 pounds, and 
to cause the wheat to lodge very badly, the plants to rust, and to 
produce, even when not attacked by rust, shrunken wheat. The 
results in 1915 were of the same character as in 1913, but owing to 
the frequent, light rains and the very luxuriant growth of the plants, 
the lodging and rusting were worse than in 1913. The yield of the 
Defiance on the plots that were dressed with sodic nitrate ranged 
from 9 to 13 bushels of very badly shrunken wheat. The wheat of 
this variety. Defiance, was all badly shrunken in 1915, but the plots 
which had received an application of sodic nitrate produced much 
poorer grain than the others; it was so badly shrunken that it could 
scarcely be considered grain at all. There can be no question but 
that the sodic nitrate tends to produce shrunken wheat, but in both 
1914 and 1915 the most important cause was rust on the plants. 
The following data will enable the reader to judge of the effects 
of the various fertilizers upon the development of the plant as grown 
under our conditions. The following table gives a sort of correla¬ 
tion of these effects: 
