18 BULLETIN 981, U. S. DEPARTMENT OF AGRICULTURE. 
season, and not a few have reported success with it on sandy lands. 
On sandy land at Valentine, Nebr., it made the following yields of 
hay to the acre: In rows 42 inches apart, 0.61 ton; in rows 21 inches 
apart, 0.83 ton; and in drilled seedings, 0.87 ton. 
At Grand Rapids. Mich., it grew to a height of 5 feet on sandy 
soil and made a better yield than any other ieee hay plant on trial. 
DRAIN AGE. 
A wet, muggy, or seepy soil is disastrous to Sudan grass, and thor- 
ough fgaec must be provided for such soils before one can hope to 
succeed with this grass. Soils not naturally well drained should be 
tile-drained at least one year previous to seeding, so that the ground 
will have an opportunity to become warm. Cold, wet soils are par- 
ticularly unsuited to Sudan grass, and this is the chief reason why 
early seedings are so often failures. 
ACIDITY AND ALKALI. 
Sudan grass is not as susceptible to injury from acid soils as the 
legumes. Applications of lime are required only when the soil is 
too acid for the ordinary cereals. 
Several tests of Sudan grass on alkali soils Wane been made, and 
its behavior under such conditions is about the same as that a the 
sorghums. A number of other crops are far more resistant to alkali 
than is Sudan grass. 
CLIMATIC ADAPTATIONS. 
TEMPERATURE REQUIREMENTS. 
Sudan grass grows best in a warm climate with a comparatively 
good rainfall. During germination and early growth it will endure 
as much cold as other sorghums, but not quite as much as corn. 
Numerous reports from the Northwestern States show that Sudan 
grass a few inches high withstood late spring frosts which killed other 
tender plants. Im many of these instances the grass remained 
practically dormant during the period of low temperatures, but 
made a vigorous growth when warm weather arrived. In other 
cases frost killed the young Sudan grass. Still other reports have 
been common from cold regions to the effect that the crop lived 
through the season but was of a yellowish color and did not grow 
more than 6 to 18 inches high even after warm weather came. 
Because of the untimely frosts and the cold growing season Sudan 
grass does poorly at the higher altitudes. The farther south, the 
higher the altitude limit. The profitable limit for hay production 
seems to be from 6,000 to 8,000 feet in New Mexico, Arizona, California, 
Nevada, Colorado, and Utah, and 4,000 to 5,000 feet in Wyoming, 
Montana, Idaho, Oregon, and Washington. In several tests reported 
