BARLEY IN THE GREAT PLAINS AREA. 31 
has yielded a fraction of a bushel higher. At Dickinson and Edgeley 
the yields on disked corn ground have been appreciably higher than 
on summer tilled-land. While the averages of all the stations are 
not strictly comparable, summer tillage has increased the yield over 
the fall plowing and the spring plowing of cropped land nearly one- 
half. The average increase over disked corn ground has not been 
nearly so great. 
These increases in yields have not been in proportion to the in- 
creased cost of the method. In no case has summer tillage been the 
most profitable method under trial. As values and costs are here 
figured, this method shows a profit at only four stations, Judith 
Basin, Williston, Dickinson, and Hettinger. At Scottsbluff, North 
Platte, and Hays the losses have been small. At the other seven 
stations they have been sufficiently great to discourage hope of 
changing them to profits by the extension of the record or by an 
adjustment of value or cost. 
Green manuring for barley has been tried at only two stations, 
Huntley and Hays. At Huntley, where it was in comparison with 
only spring-plowed land and disked corn ground, it gave the highest 
average yield. This average is the highest resulting from any. 
method at any station. The record, however, is for only two years. 
At Hays its yield has been greater than that on land from which a 
crop was harvested, but not as high as that on summer-tilled ground. 
On the whole, differences in climatic conditions of different seasons 
have produced much wider variations in yields than have resulted 
from differences in cultivation. Some seasons have a combination 
of climatic factors so adverse as to produce failures by all methods 
of tillage at some stations. Other seasons have conditions so favor- 
able that any and all methods of tillage produce good crops. Still 
other seasons prohibit production by some methods, but allow it 
with others. The greater the number of years averaged the more 
nearly will the final figure represent average seasonal conditions. 
This longer average will also tend to reduce the wide differences 
that may result between methods during some seasons especially 
favorable to some particular method. No method so far tried, 
however, has been able to overcome the extremely unfavorable con- 
ditions which sometimes exist. 
CONCLUSIONS. 
(1) Differences in the climatic conditions of different seasons have 
caused much wider variations in yields than have resulted from dif- 
ferences in cultivation. 
(2) Yields at Belle Fourche, Garden City, Dalhart, and Amarillo 
have been markedly lower than those obtained at the other field 
