148 



THIRD ANNUAL SESSIONS 



sweet clover was relatively considerable less at Edgeley than at any of 

 the other stations where that method has been tried. It is well to bear 

 in mind in this connection that the yields for Highmore represent the 

 average results for three years, at North Platte for two years, and at 

 Edgeley for two years. It is quite probable that if we had two or more 

 year's results from Dickinson and Amarillo that the curves would be 

 smoother and the average results would correspond more nearly to those 

 obtained at the other stations and consequently more nearly with the 

 average. The yields obtained at Hayes were very unsatisfactory and 

 might properly have been omitted from this diagram were it not for the 

 fact that we wished to include all of the available data. The crop was 

 injured by grasshoppers and attacks of rust so that the yields were not 

 dependable. 



Average Results. 



"We will now consider the lower half of the diagram (Page 145) which 

 indicates the yields of wheat under the same methods of treatment already 

 described for the oat crop. It will be noted that there is a general co- 

 incidence between the average curve for wheat and the average curve 

 for oats, the most marked exception being the reduced yields obtained 

 from the wheat crop following oats on spring plowed land, which was 

 only 13.2 bushels as against 17.2 bushels for the wheat crop following 

 oats on fall plowed land. The average yield of 22.4 bushels of wheat 

 upon fallow or summer tilled land shows the difference of 4.4 bushels 

 as compared with the wheat on disked land. 



Soil Fertiiization. * 



"Plowed under rye, peas and sweet clover all gave better results 

 than summer tilled, the difference, however, being but slight. The re- 

 sults from the several stations correspond more nearly with wheat than 

 with oats. There are, however, many marked exceptions. Amarillo 

 and Dickinson disagree in much the same way with wheat as they did 

 with oats, although not to such a marked extent. Edgeley and Highmore 

 correspond more closely with the average for all the stations. The wheat 

 crop at North Platte seems to have been more susceptible to difference 

 in cultivation than any except Dickinson, but as the results at Dickin- 

 son are for only one year while those at North Platte are for two years, 

 the annual effects each year at North Platte are greater than at Dick- 

 inson, as will be shown when we come to examine the diagram show- 

 ing the yields for each year separately. 



Wheat and Oats. 



"Diagram No. 3 (Page 149), represents the yield of wheat and oats at 

 Edgeley, N. D., for two years, the broken line being fbr 1907 and t3ie 

 solid line for 1908. It will be noticed that the effect upon the yield of 

 oats due to the different sequences and the time of plowing corresponds 

 very closely for the two years, the only marked exception being that fall 

 plowed oat land gave 6.2 bushels higher yield than spring plowed corn 



