2,6 The Colorado Experiment Station 
in gluten, flintier, with great absolute weight and a higher weight per 
hectolitre.” 
The effect of crop rotation is well illustrated by a case observed 
by Prof. Keyser while he was connected with the U. S. Depart¬ 
ment of Agriculture and stationed in Nebraska. Prof. Keyser has 
fully stated this case in a letter addressed to me on the subject and 
with his permission I state it in his own words: 
“A certain field in York county, Nebraska, had grown corn for a 
number of years. A portion of the field had been seeded down to clover. 
The year the clover was broken up the corn land was seeded to oats. The 
clover and oat stubble were broken up and the entire field seeded to Tur¬ 
key Red winter wheat. The year was favorable to good production and 
a good yield was returned on both parts of the field. The wheat from 
the land which had been in corn a number of years, however, contained a 
very high percentage of yellow-berry, although it was otherwise of good 
quality. The wheat on the clover sod, however, had very little yellow- 
berry, although there was an occasional kernel in evidence. Aside from 
this difference there was very little difference to be detected in the wheat 
from both parts of the field. 
“The owner sent the wheat to the Nebraska State Fair, sending sam¬ 
ples from each portion of the field. There was no appreciable inferiority 
of the yellow-berry wheat except the presence of the yellow-berry, both 
samples being unusually good. As I remember it, this wheat was seeded 
in the fall of 1902, harvested in 19 03 and exhibited that fall.” 
It is altogether in keeping with what we believe about the ef¬ 
fects of various crops to assume that the corn and oats had ex¬ 
hausted the available nitrogen in that portion of the field which 
had been planted successively to these crops, while the clover had 
actually added nitrogen to the soil increasing the ratio of the nitro¬ 
gen supply to that of the potassium with the results above given. 
Prof. Keyser states that the yield was a good one and that the 
samples of wheat exhibited were unusually good, therefore, we are 
free to infer that the land had not been exhausted so 1 far as crop 
production was concerned nor was the wheat affected with any 
other trouble than yellow-berry. 
There is still another way to reduce or prevent the trouble, it 
is to cultivate the land fallow for one season during which some 
of our lands will acquire nitrates enough to produce a crop of wheat 
but little affected with yellow-berry. The department of agronomy 
under Prof. Keyser is conducting experiments with wheat on land 
sixteen feet to the west of that on which I am conducting my ex¬ 
periments. I am cropping continuously and he is cropping and 
cultivating fallow alternate years. The grain on my check plots 
comparable to his land produced wheat in 1914 having 97 and 98 
percent yellow-berry, his wheat showed 14 percent yellow-berrv. 
