40 BULLETIN 1244, U. S. DEPABTMENT OF AGRICULTURE. 



tively short cool season. In a test at Williston in 1915 it was con- 

 cluded that the forage possibilities were small, although two varieties 

 that matured yielded at the rate of 10 bushels of seed per acre. 



GRASSES. 



The fact that cultivated perennial grasses constitute such a small 

 proportion of the acreage of the northern Great Plains region is a 

 good indication that the yields of the grasses have not been very 

 satisfactory. According to the last census, the average yield of 

 timothy alone is appreciably less and that of timothy and clover 

 mixed is slightly more than 1 ton per acre. Most of the timothy, 

 either alone or in mixtures, is grown in the eastern part of the region, 

 or farther west under irrigation. Timothy has been tested under 

 dry-land conditions at various stations, but the yields have generally 

 been too light to justify a farmer in growing the crop. Awnless 

 brome grass (Bromus inermis L.) up to the present time has proved 

 most satisfactory in all the tests at the dry-land stations and is about 



Fig i. A field of crested wheat grass (Agrdpyron cristatum) at Moccasin, Mont., in 1920. This 



is one of the most promising perennial hay grasses for the northern Qreal Plains region. 



the only perennial cultivated grass that is grown on dry land. Over 

 much of the area even this grass is not capable of giving profitable 

 yields, except in favorable locations that receive the benefit of 

 additional moisture. Under such conditions brome grass gives the 

 best yields the first two years. After this the grass becomes sod 

 bound and the yields are inclined to fall oil' unless an abundance vt 

 moisture is available. No census figures are available concerning 

 the acreage of brome grass, but it is undoubtedly considerably less 

 than that of timothy, and the average yield of liny per acre is probably 

 less than a. (on. 



Slender wheat grass (Agropyron tenerum L.), which has been grown 

 to a limited extent in many parts of the region, has gained little bead- 

 way in acreage. 



Crested wheat grass {Agropyron cristatum L.) offers considerable 

 promise as a hay crop (fig. 17). Its performance in the tests at the 

 various stations indicated its possibilities. The results of tin 4 bests 

 with these various grasses are shown in Table 23. 





