12 BULLETIN 1304, TJ. S. DEPARTMENT OF AGRICULTURE 
tively low yields in this group are not due to the continuity of winter 
wheat but to the immediate preparation as it affects the quantity 
of water in the soil. Practically the same results would be obtained 
following any small grain in a rotation. The heaviest yielding of 
these methods is deep early-fall plowing, which gives a 15-year aver- 
age of 10.5 bushels per acre. By this method 2 acres will produce 
21 bushels of wheat in one year and in an alternate fallowing and 
cropping system 19.1 bushels. The poorest yielding method under 
trial is late, shallow, fall plowing, with an average of 9.1 bushels per 
acre. The evidence indicates that the difference in yield between 
this plat and the one plowed deep in the early fall is due to the time 
of plowing and the consequent differences in the seed-bed prepara- 
tion as affecting the quantity of water in the soil rather than to the 
differences in the depth of plowing. 
The subsoiled plat is plowed at the same time and cultivated and 
otherwise treated the same as the deep early-plowed plat, except 
that it is subsoiled at the time of plowing. Subsoiling is done for 
two years and then omitted for two years. The average yield from 
this plat is 1.3 bushels per acre less than that from the plat not 
subsoiled and but 0.1 bushel more than the yield from the plat 
plowed shallow late in the fall. The yield is 0.9 bushel less than the 
yield from listing, which is a much cheaper method of soil prepara- 
tion. These results give no support to the practice of subsoiling 
for this region, so far as the winter-wheat crop is concerned. 
One plat is listed at the time early plowing is done. Before seeding 
time it is disked level. This takes less time than plowing. The 15- 
year average yield from this method is 10.1 bushels, as compared to 
10.5 bushels from deep early-fall plowing. It appears that listing 
soon after harvest and subsequently working the ground level, 
cultivating after each consequential rain, is as good as plowing. 
No winter wheat has been grown at this station on disked or 
uncultivated small-grain stubble, but a thorough investigation of 
these methods is to be undertaken. Results at some other stations 
have been remarkably favorable to the omission of plowing under 
certain conditions. 
Experience has shown that it is not possible to estimate accurately 
the winter-wheat survival at the early date that the spring small 
grains must be seeded if they are to yield their best. Of the spring- 
sown small-grain crops that might be used for reseeding, barley or 
oats are most likely to give a return commensurate with the effort. 
Barley even seems to show a little more versatility than oats in return- 
ing a fair yield under unfavorable circumstances. The spring-sown 
small grains should not be seeded later than April 10. 
Winterkilled winter-wheat ground would serve better for millet, 
beans, corn, or sorgo, any of which gives ample time to determine 
the value of the winter- wheat stand. Millet and corn may be seeded 
May 15 and beans and sorgo as late as June 1. 
RESULTS WITH SPRING WHEAT 
The 15-year average yield of spring wheat is 10.3 bushels per acre, 
as compared with an average of 12.8 bushels for winter wheat. 
Spring wheat produced a higher average yield than winter wheat in 
only 5 of the 15 years, and in 2 of these 5 years the average yield of 
