INVESTIGATIONS AT ARDMORE, S. DAK. 



15 



Table 6. — Average annual acre yields (pounds) of crops under 8 different 

 sequences at the Ardmore station for the 20-year period, 1913-32 





Average acre yields 



Crop 



After small 

 grains 



After culti- 

 vated crops 



After fallow 



Spring wheat 



Pounds 

 720 

 528 

 877 

 926 



Pounds 



990 



774 



1,034 



1,243 



Pounds 

 1,146 





1,104 



Oats.. 



1,322 



Barley - --- 



1,522 







With all crops and for all sequences winter wheat made the 

 lowest yields per acre, spring wheat the second lowest, oats next, and 

 barley the highest. The yield of spring wheat was much higher than 

 that of winter wheat on soil preparations other than fallow. This 

 indicates that if winter wheat is to be grown at all it should be 

 grown under the best possible conditions. When grown under ordi- 

 nary methods, spring wheat is much more productive than winter 

 wheat. 



The relatively low yield of winter wheat on corn stubble is due 

 partly to soil blowing. Recognition of this fact led to the addition 

 of a rotation in which winter wheat was planted in standing corn- 

 stalks. Five years' results are available from this rotation. During 

 this period the yield of winter wheat in this rotation was materially 

 higher than that of winter wheat following harvested corn, and 

 slightly higher than that of spring wheat on corn ground. 



For the period for which records are available, seeding winter 

 wheat in standing cornstalks offered the greatest possibility of suc- 

 cess with that crop of any method under trial. All the years in 

 which this rotation was used were years of drought injury, in which 

 the snow held by the cornstalks was of material benefit. Without 

 exception, the stands of wheat in this rotation were better than those 

 on corn ground from which the corn was harvested with a binder, 

 the difference in stand being due to lack of injury by soil blowing 

 in the plot protected by stalks. 



Oats were more productive than spring wheat in all three se- 

 quences, the smallest difference being shown on corn ground. The 

 differences in yield on other methods of cultivation are not great 

 enough to make up for the difference in price, if grown for sale. The 

 results clearly indicate that if oats and wheat are both grown, the 

 corn ground should be planted to wheat. 



Barley was more productive than oats in all three sequences. The 

 difference was much greater after corn and fallow than after small 

 grain, which indicates that barley should be given the preference in 

 the better crop sequences. For the 11-year period in which White 

 Smyrna was used, barley on fallowed land and on corn ground 

 produced over 500 pounds per acre more than oats on corresponding 

 methods of cultivation. 



Barley is the most productive small-grain crop. The growth of 

 an adapted variety of barley and the selection of a livestock-pro- 



