32 BULLETIN 595, U. S. DEPARTMENT OF AGRICULTURE. 
and North Platte stations. At the other stations the yields from 
this method have not been sufficient to pay the cost of producing 
them, and the losses have been greater than the losses from any other 
method. 
It is hardly fair to charge the whole expense of green manuring to 
the one crop that immediately follows it, as is done. This method 
should have a cumulative effect in building up the soil or remedying 
its deficiency in organic matter. The available evidence is that on 
normal soils on the Great Plains, at least in the first years of the work, 
little effect is shown on other than the first crop. This effect is that 
of a fallow to the extent that the green manure approaches a fallow 
in the storage of water during the period after the crop is plowed 
under. 
COMPARISON OF WINTER WHEAT WITH SPRING WHEAT. 
Table XIX shows the average yields and profit or loss for winter 
wheat and spring wheat by the different methods under which both 
of these crops are grown at the 13 stations. This table also gives the 
average yield and average profit or loss for all of the methods used 
with each of these crops at each of the stations. The yields from the 
various methods are comparable for the two crops at each station. 
The figures used in computing the profit or loss for spring wheat 
are the same as those used in Table IV in United States Department 
of Agriculture Bulletin No. 214, entitled ‘“‘Sprmg Wheat in the Great 
Plains Area.’’ Because winter wheat is seeded in the fall, the cost of 
preparing the ground by the various methods is less than for spring 
wheat. 
At the North Platte, Akron, and Hays stations winter wheat has 
been distinctly more productive than spring wheat under all methods 
tried. The greatest differences between the yields of winter wheat 
and spring wheat have been secured at Hays, where the differences 
in favor of winter wheat range from 8.6 bushels per acre on disked 
corn ground to 15.7 bushels on summer tillage. At Tucumeari the 
yields of spring wheat have been greater than those of winter wheat 
from the methods under which both crops are grown. The average 
yield from all the methods used with both crops is decidedly in favor of 
winter wheat at Huntley and somewhat in favor of winter wheat at 
Belle Fourche, Scottsbluff, and Amarillo. At the other stations the 
average yield of spring wheat is slightly greater than the average yield 
of winter wheat. 
The average yield from summer tillage has been decidedly in favor 
of winter wheat at Judith Basin, Huntley, Belle Fourche, Scottsbluff, 
North Platte, Akron, and Hays. At Garden City, Dalhart, and 
Amarillo the average has been slightly in favor of spring wheat, while 
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