Sept. 9.1918 Deep Tilling and Dynamiting in the Great Plains 
505 
DEEP TILLING BY THE USE OF DYNAMITE OR SPECIAL PLOWS 
Experiments have been conducted with both dynamite 1 and the Spald¬ 
ing deep-tilling machine at the Hays and Akron stations, and with 
dynamite at the Ardmore, Bellefourche, and Judith Basin stations. 
HAYS FIELD STATION 
DEEP TILLING BY THE USE OF DYNAMITE AND SPECIAL PLOWS 
In 1913 a series of experiments was started at Hays, Kans., to deter¬ 
mine the effect of different methods of preparing the land for winter 
wheat in a series of three-year rotations of fallow, winter wheat, and kafir. 
In this series four rotations, No. 501, 502, 503, and 504, are identical 
except as noted below. In No. 501 the plowing for the fallow is done 
with a Spalding deep-tilling machine, which plows the soil to a depth of 
from 12 to 14 inches. This plowing is done in the fall, preceding the 
fallow season, or practically an entire year before seeding to winter 
wheat. In rotation 502, dynamite is used in the fall. After dynamiting, 
the land is furrowed with a lister, the same as in rotations 503 and 504. 
In dynamiting, 18 shots of half sticks of 20 per cent powder placed 3 feet 
deep are fired on the tenth-acre plot, the distance between the shots 
being 16 feet. The plots to be fallowed in rotations 503 and 504 are 
furrowed out with the lister in the fall preceding the fallow season. 
These two rotations are identical except that the wheat stubble in No. 
503 is disked after harvest, while that in No. 504 receives no cultivation 
until both are furrowed with a lister in the fall. All the fallow plots are 
given necessary cultivation to keep them free from vegetation during 
the fallow year. These rotations were begun in the spring of 1913, but 
the crops that year were a failure. The first dynamiting and deep 
tilling was done in the fall or 1913. The land so treated was fallow in 
1914, so the first crop of wheat on plots differing in their treatment was 
harvested in 1915. The first kafir following the wheat on the plots 
differently treated was produced in 1916. 
In Table XIV are given the yields of both winter wheat and kafir for 
the three years 1914, 1915, and 1916. There are thus shown one wheat 
crop, 1914, on land uniform in preparation, and two wheat crops, 1915 
and 1916, on land differing in its treatment. With the kafir crop the 
preparation of the various rotations was uniform for the crops of 1914 
and 1915, but was differentiated for the crop of 1916. To facilitate com¬ 
parisons, the data in this table are shown in two forms. Eirst, the yield 
in bushels, and second, the ratio of these yields to the mean yield of the 
four plots for each year. The data from plots differing in their treat¬ 
ment are shown in boldfaced type. 
1 The E. I. du Pont de Nemours Powder Co. furnished the material for the dynamiting experiments 
and experts to direct the operations at the different field stations. 
