16 BULLETIN 1094, U. S. DEPARTMENT OF AGRICULTURE. 
barley from the rye rotation. It is doubtful whether the differences 
are significant. 
The corn in these five rotations has made only three good crops. 
Some of the losses have been from grasshoppers and chinch bugs. 
These concentrate on the plats from the grain fields by which they are 
surrounded and sometimes cause losses which large fields would not 
suffer. To that extent the average may not be equal to the average 
that corn may attain in the section. But some of the losses have 
been from drought and hot winds, which are no more serious on plats 
than on larger fields. 
The two rotations containing kafir have made average yields of 
18.3 bushels of kafir grain and 4,648 pounds of stover in rotation 
No. 55, containing rye for green manure; and 20.3 bushels of grain and 
4,698 pounds of stover in rotation No. 56, containing peas for green 
manure. Barley following the kafir has averaged 17.5 bushels in 
rotation No. 55 and 19.2 bushels in rotation No. 56. These yields of 
barley following kafir compare favorably with those following corn 
and are very nearly equal to the yields of barley following imme- 
diately after green manure. Barley in alternation with fallow on 
plats not previously introduced into this discussion has averaged 23 
bushels per acre for the same period of years. The wheat in the rye 
rotation has averaged 16.5 bushels and in the pea rotation 15.5 
bushels. These rotations clearly show the superiority of kafir over 
_ corn in the production of both grain and stover. The other crops in 
the rotations show no disadvantage from the kafirin them. Unfor- 
tunately there is not in this block any winter wheat immediately fol- 
lowing kafir. The extent of work that could be started originally 
was limited, and the general experience and belief that wheat did not 
follow the sorghum crops successfully was accepted as sufficient rea- 
son for not including this method. | 
Two other rotations in this block introduce sod crops. Rotation 
No. 141 is oats on brome-grass sod, corn on spring-plowed oat stubble, 
winter wheat on disked corn ground, and three years of brome-grass. 
For several years the grass seed was sown in the winter wheat in the 
spring, but a stand was never obtained in this way. After failure to 
obtain a stand by this method the wheat stubble was plowed in the 
fall and the brome-grass seeded in the spring. Better results attended 
this method, but it is not always possible to get a stand and bring it 
through the summer. The rotation has been a failure as far as the 
grass crop is concerned. The only hay harvested was in 1916, 1919, 
and 1920. About half the time there has been a fair sod to break for 
oats. Breaking has been done in summer at the time of fall plowing. 
Oats have averaged 20 bushels per acre in this rotation, which is 
about the same as the average following grain crops, but in the 
years when a heavy sod has been broken the yield has been low. 
