CEREALS ON THE BELLE FOURCHE EXPERIMENT FARM. 51 
DEPTH-OF-SEEDING EXPERIMENTS. 
Depth-of-seeding experiments with Kharkof winter wheats were 
conducted on irrigated land in 1917 and 1918. Only one fiftieth-acre 
plat was sown at each depth in 1917, but in 1918 the experiment was 
) triplicated. The yields are shown in Table XXXVII. 
Table XXXVII. — Yields of Kharkof icinter wheat grown in depth-of-seeding 
experiments on irrigated land in 1917 and 1918. 
Depth of seeding. 
Yields per acre (bushels). . 
1917 
1918 
Average. 
1 inch 
24.5 
30.0 
28.5 
35.9 
34.2 
32.3 
30.2 
1£ inches 
32.1 
2 inches . 
30.4 
In 1917 the seeding at a depth of IJ inches gave the highest yield, 
while in 1918 the highest average yield was obtained from seeding 
at a depth of 1 inch. The 1^-inch depth of seeding gave the highest 
average yield for the two years and, although the results are not 
very conclusive, this appears to be the most favorable depth. 
COMPARISON OF SPRING AND WINTER WHEATS. 
In 1916, 1917, and 1918, three plats of Kubanka durum spring 
wheat were sown in the spring in the same series with the winter- 
wheat varieties for comparison. During each of these years Ku- 
banka considerably outyielded all of the winter- wheat varieties. In 
1915 the winter wheat was sown under very favorable soil conditions 
and the yield was unusually high. The 4-year average yield of 
Kharkof, C. I. No. 1583, winter wheat was 32.6 bushels per acre, 
while Kubanka spring wheat yielded an average of 27.3 bushels. 
Because of the conditions in 1915, however, these yields are not quite 
comparable. 
In the irrigated rotation experiments on the Belle Fourche Ex- 
periment Farm, conducted by the Office of Western Irrigation Agri- 
culture, spring and winter wheat have been grown in continuous 
culture in adjoining plats each year since 1913. Since 1915 this test 
has been duplicated in another part of the rotation field on better 
soil. The yields on this good soil have been nearly twice as high as 
on the poorer soil. The average yields from the good and poor 
plats are used for comparison from 1915 to 1919, inclusive. The 
same variety of spring wheat was not used during all seasons. From 
1913 to 1915, inclusive, Kegenerated Defiance, C. I. No. 3703, was 
the variety used. In 1916 Marquis, C. I. No. 3276, was sown, but 
since 1917 Kubanka durum spring wheat was used. Because of the 
