CEREALS OK" THE BELLE EOURCHE EXPERIMENT FARM. 
69 
Primost flax, C. I. No. 12, was given a late irrigation on July 25, 
while an adjoining plat of the same size was not irrigated. Both 
had been irrigated 15 days previous. When this late irrigation was 
applied the flax had practically completed blooming and most of the 
bolls were formed. 
The late irrigation caused considerable late blooming, perhaps a 
third more than occurred on the check plat. Maturity was delayed 
only three days as compared with the check plat not irrigated. The 
plat receiving the late irrigation yielded at the rate of 15.7 bushels 
per acre, while the adjoining plat yielded only 13.3 bushels. The 
season was dry and warm, so that the increased soil moisture proved 
to be beneficial. This might not always occur, but it indicates that 
flax may be irrigated after blooming in most seasons without injury. 
TILLAGE EXPERIMENTS. 
Most of the spring grains under irrigation were sown on disked 
corn ground. The soil was a heavy clay and usually quite compact 
at the time of seeding, even after being double disked and harrowed. 
An experiment in tillage treatment of corn ground in preparation 
for spring grain was conducted during the 1915-16 crop year. The 
plats were all one-fiftieth of an acre in size. 
Thirteen plats were plowed in the fall to a depth of 7 or 8 inches, 
13 were subsoiled about 12 inches deep in the fall, while the 13 
remaining were not touched until spring. Plowing was done with 
a disk plow. The subsoiler was run twice between the rows of corn 
stubble on unplowed land. In the spring all plats were double 
disked and floated alike and all subsequent treatment of the plats 
was the same. 
The plats were sown to Kubanka wheat, Swedish Select oats, 
Chevalier barley, and Primost flax. Three plats each of wheat, 
barley, and flax and four plats of oats were sown on ground repre- 
senting the three different tillage treatments, making a total of 39 
plats in the experiment. Because of soil blowing, rust, and the 
presence of considerable wild oats, the yields obtained were not large. 
The yields from the experiment are shown in Table LIII. 
Table LIII. — Yields of spring ivheat, oats, barley, and flax groion following a 
corn crop in a tillage experiment on irrigated land on the Belle Fourche Ex- 
periment Farm in 1916. 
Yields per acre (bushels). 
Fall tillage. 
Kubanka 
wheat. 
Swedish 
Select 
oats. 
Chevalier 
barley. 
Primost 
flax. 
Plowed 
16.7 
40.6 
39.8 
41.1 
18.5 
18 1 
9 7 
16.3 
17.8 
