CEREAL CULTIVATION GREAT PLAINS 347 



duction has in most cases in these investigations, proved 

 a more important factor in determining profits than in- 

 creasing yields by cultural methods." 



374. Cereals following a cultivated crop. The results 

 just described, together with, those of other rotations 

 conducted in this country and Canada, including a cereal 

 following potatoes or a root crop, show conclusively that 

 cereals always give excellent results after a cultivated 

 crop, and confirm a previous statement that the latter 



FIG. 106. Corn and sunflowers as an intertilled crop, preceding winter 

 wheat, in the Molochna Valley, Taurida, Russia. 



should be included in every rotation (342). The culti- 

 vated crop is particularly essential in the Great Plains, as 

 it affords not only the benefit of the storage of soil mois- 

 ture, the most important feature of cropping \n that area, 

 but also promotes the eradication of weeds. In southern 

 Russia, where such a crop sequence is practiced, sun- 

 flowers grown for the seed sometimes form a part of the 

 cultivated crop (Fig. 106). 



A striking example of the influence of corn cultivation 

 on a succeeding crop of small grain was shown at High- 



