144 



THIRD ANNUAL SESSIONS 



Experimental Stations. 



"The reason for the selection of six of these stations and the exclu- 

 sion of the other five is that~the work at only six of them had progressed 

 far enough to give results that can be considered in this connection. 

 The six stations having been in operation for periods varying from three 

 to five years, the results have been used in the accompanying diagrams. 

 As the results "of crop sequence do not become apparent until the second 

 year, but a single year's results are available from Dickinson, Hays and 

 Amarillo, two years' results from Edgley and North Platte, and three 

 years' results from Highmore. 



Wheat and Oats. 



"A considerable number of crops were raised at each of these 

 stations, but it was considered desirable to confine this discussion to 

 two of the principle crops. We have, thereore, selected wheat and oats 

 for this purpose. All of the- yields from the plats raising these crops 

 at all six of these stations for the time covered have been used, except 

 in a few cases where, due to error or accident of some kind, the results 

 were known to be inaccurate, and, therefore, not comparable with other 

 results given. No effort whatever has been made to obtain evidence 

 for the support of any theory or hypothesis. We have simply brought 

 together all available data having a bearing upon these two crops grown 

 at these six stations. We do not consider this data sufficient to warrant 

 any definite conclusions. We do feel, however, that they are sufficient 

 to show something of the limitations and possibilities of this work when 

 carried on for a sufficient length of time. In the discussion of the fol- 

 lowing diagrams we will endeavor to point out some of these limitations 

 and possibilities. 



Acreage Results. 



"Diagram number two represents the yields of oats and wheat as 

 affected by soil preparation and crop sequence at the six stations men- 

 tioned. The vertical columns numbered from one to thirteen indicate 

 the various crop sequences and times of plowing as is set forth in the 

 legend at the bottom of the diagram. The marginal figures at the right 

 and left sides of the diagram indicate the yields in bushels of oats in 

 the upper half of the diagram and of wheat in the lower half of the 

 diagram. The heavy solid lines crossing the diagram irregularly from 

 right to left indicate the average yields obtained at all of the stations 

 under different crop sequence and times of plowing, the one in the upper 

 half being for oats and the lower half for wheat. The six double or 

 broken lines each represent the yields obtained at one of the six stations, 

 as is indicated by the name affixed to the line. 



Crop Rotation. 



"Let us first consider the heavy solid line in the upper half^ of the 

 diagram, which represents the average yield of oats obtained. It will 

 be noticed that on the average there was very little difference in the 



