CEREAL CULTIVATION GREAT PLAINS 357 



when following another crop, in fact permits a brief 

 summer tillage. At the Kansas station, Call (1913, p. 7) 

 investigated this subject as to winter wheat, both in a 

 rotation with corn and oats and in continuous wheat 

 cropping. The best date and depth of plowing, consider- 

 ing both yield and cost, was the plowing July 15, 3 inches 

 deep, in case of the rotation, giving a yield of 44 bushels 

 to the acre and net profit above cost of preparation of 

 $30.91. In the continuous cropping, the best results 

 were from plow- 

 ing July 15, 7 

 inches deep, the 

 acre yield being 

 35 bushels, and 

 net return above 

 cost of prepara- 

 tion $23.11. The 

 average results 

 for 3 years, in 

 continuous crop- 

 ping, were in 

 favor of deep 

 plowing (Fig. 

 110). Grace 

 (1915, p. 6) gives 

 results of 6 years' 



trials of early and late plowing for winter wheat, in 

 which the yields from early plowing were always better. 

 Double-disking early after harvest, followed by plow- 

 ing within a month afterward, is found to be a good plan, 

 particularly if the ground cannot be plowed or listed at 

 time of disking. Weeds are killed and moisture is held 

 in the soil. Disking without plowing is a poor method. 



FIG. 110. Comparison of different methods 

 of preparing the ground for winter wheat in 

 continuous cropping : A, Plowed July 15, 3 

 inches deep; B, Plowed July 15, 7 inches 

 deep; C, Disked at planting, not plowed; 

 D, Plowed August 15, 7 inches deep; E, 

 Plowed September 15, 3 inches deep. 



