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 Kapids. Mich., it grew to a height of 5 feet on sandy 

 soil and made a better yield than any other annual hay plant on trial. 



DRAINAGE. 



A wet, muggy, or seepy soil is disastrous to Sudan grass, and thor- 

 ough drainage 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 have been made, and 

 its behavior under such conditions is about the same as that of 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. In 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 



