CEREAL CULTIVATION GREAT PLAINS 343 



is being tried, but so far does not appear promising. The 

 cost of green-manuring is great comparatively, and may 

 be sufficient to eliminate the practice in this area, unless 

 the residual effects of these manures should be consider- 

 able. 



370. Results of experiments in green-manuring. - 

 Chilcott, Cole, and Burr (1915a, p. 43) report that " the 

 most expensive method (of spring wheat production) under 

 trial is green-manuring. It has produced less profit or 

 greater loss than any other method under investigation." 

 They also found that green-manuring for barley production 

 gave the highest yield at Huntley, Montana, where it was 

 in competition with spring-plowed land and disked corn 

 ground, in only a 2-year test. The green crops turned 

 under were rye and peas. The net profit in this soil 

 treatment was $3.45 to the acre against $9.50 for disked 

 corn ground and $6.15 for spring-plowed land. Green- 

 manuring was also followed by higher yields of oats than 

 either fall or spring plowing or disked corn ground at 

 9 out of 13 stations. However, " the cost of produc- 

 tion by this method was so high that it showed a profit 

 at only 2 stations" (Chilcott, Cole, and Burr, 1915b, 

 1915c). It is significant that the only stations, Huntley 

 and Judith Basin, Montana, where grain followed green- 

 manures with a profit in all these experiments of the 

 United States Department of Agriculture are on the 

 border of the Western area where the addition of humus 

 is one of the chief problems (70-72). 



371. Rotation of crops. One of the purposes of crop 

 rotation is the same as that of green-manuring, to add 

 humus to the soil. In the Great Plains a more important 

 present purpose for cereal cropping is the storage of soil 

 moisture effected through a previous cultivated crop. 



