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 



