“I 
NORTHERN GREAT PLAINS FIELD STATION, 1913-1922 ) 
alfalfa entirely winterkilled in 1919-20, and a satisfactory stand was 
not again obtained until 1922. The yield of field-cured hay from 
l-year-old and 2-year-old sod in this rotation has averaged about 
1,900 pounds per acre. 
The variety was Grimm. It was seeded at the rate of 5 to 6 
pounds per acre. 
BROME GRASS 
This grass is sown on disked corn ground, with wheat as a nurse 
crop. The rate of seeding is 10 to 15 pounds per acre. The brome 
grass occupies the ground for three seasons after the year of seeding. 
A satisfactory stand was not obtained during the four seasons 1918-— 
1921, so the yields obtained have been low. Brome grass in this 
rotation has yielded from 1,000 to 1,600 pounds of hay per acre on 
the average, depending upon the age of the sod. 
POTATOES 
Early Ohio potatoes are grown in two 4-year rotations. The 
potatoes are planted on spring-plowed ground following wheat in one 
rotation and oats in the other. There has been no marked difference 
in the results following the two crops. The vields have ranged from 
50 to 180 bushels per acre, with average yields between 100 and 110 
bushels per acre. In 1921 the potatoes were of poor quality, and 
only approximately 25 per cent was fit for table use. 
SORGO 
Sorgo, as a forage crop, appears in one 3-year rotation. The 
average yield for the eight years 1915-1922 was 3,264 pounds per 
acre, which is less than that of the same variety (Dakota Amber) 
in the variety tests, which usually have been sown on spring-plowed 
ground. Corn in a similar 3-year rotation yielded less than the sorgo 
during the dry years 1919, 1920, and 1921, but exceeded the sorgo in 
yield the other years and averaged better for the eight years. 
GREEN-MANURE CROPS 
Sweet clover, winter rye, and peas are grown in different four-year 
rotations and plowed under for green manure in preparation for both 
wheat and oats: Peas are sown on fall plowing, following both oats 
and wheat; winter rye is drilled into both oats and wheat stubble: 
and sweet clover is sown on disked corn ground with both oats and 
wheat as nurse crops. Crops of both winter rye and peas were 
plowed under each year. Sweet clover produced no crop two years, 
and only a very light yield two other years. These failures and 
partial failures were due to drought and winterkilling. 
EXPERIMENTS WITH FORAGE CROPS 
Investigations of forage-crop production have been conducted since 
the station was established. Different groups or classes of forage 
crops and different varieties of the same crop have been under trial. 
The investigations were conducted in cooperation with the Office of 
Alkali and Drought Resistant Plant Investigations of the Bureau of 
Plant Industry from 1914 to 1920, inclusive. A. C. Dillman, for- 
