NORTHERN GREAT PLAINS FIELD STATION IN 1923 15 
corn ground the yield averaged 33.1 bushels for nine years and 22.8 
bushels in 1923. The yield on summer fallow usually averages about 
15 bushels per acre higher than the yield on disked corn ground, 
but the increase is not enough to overcome the loss resulting from 
using the land two years to produce one crop. 
Barley. — The 9-year average yield of barley was 21.5 bushels per 
acre. In 1923 the average yield was 18.1 bushels. The 9-year 
average yield on summer fallow was 30.2 bushels per acre and on 
disked corn ground 23.5 bushels. The yields by all methods in 1923 
were less than the 9-year averages. 
Flax. — This crop was grown on old land in the rotations. The 
average yield was low, as wilt reduced the yields on some short rota- 
tions during the period they were under trial. A mlt-resistant 
variety is now grown in all rotations but was not used during the 
earlier years. The average yield of flax for 1923 following sod crops 
and corn was 11.9 bushels per acre. 
Corn. — The 9-year average yield of ear corn was 28.1 bushels per 
acre, as compared with 49.4 bushels in 1923. The season was excep- 
tionally favorable for the production of corn by all tillage m^ethods. 
The 9-year average yield on spring plowing was 28.9 bushels per acre, 
as compared with 26 bushels on fall plowing. During seasons of 
ample rainfall the difference in yield between spring plowing and fall 
plowing is small. 
COOPERATIVE CEREAL AND FORAGE-CROP INVESTIGATIONS 
Corn. — Varietal tests of corn are conducted in cooperation with the 
Office of Cereal Investigations. A number of different varieties are 
grown each year. Gehu Flint and Dakota White Flint are the best 
varieties among the ffints grown. Northwestern Dent and Payne 
White Dent are the leading dent varieties at the present time. The 
season of 1923 was so favorable for corn that some varieties that do 
not usually mature produced good crops. 
Forage crops. — The experiments with forage crops are now con- 
ducted in cooperation witli the Office of Forage- Crop Investigations. 
The crops that are under trial are alfalfa, sweetclover, bromegrass, 
wheatgrasses, millets, sorghums, Sudan grass, corn, sunflowers, peas, 
and root crops. A detailed report giving the yields of these different 
crops may be found in a previous publication of this station.^ 
Alfalfa seeded along a small coulee at the station has yielded 
well since 1918, the year it was seeded. In 1923 it produced nearly 
4 tons of good hay per acre in the best area. Sorgo and millet pro- 
duced on the average approximately 2 tons of feed per acre. The 
early amber varieties of sorgo are best adapted to this area. 
CONCLUSIONS FROM AGRONOMIC INVESTIGATIONS 
The highest yields of the small grains — wheat, oats, and barley — 
are obtained on summer fallow; but their growth in rotation with 
corn is considered more desirable, because they are produced with 
less labor and there is in addition a crop of corn. 
The highest yield of corn is produced on fallow, but the increase 
over the yield on either fall or spring plowing following a crop is not 
enough to make the use of fallow advisable. The average difference 
'' See footnote 2. 
