388 



GRASSES OF IOWA. 



WATER FREE SUBSTANCE. 



Sample I 1-70 | 4.17 | 3.87 | 37 64 | 6.94 | 49.64 



Switch grass {Panicum virgatum, L. ) is common and productive 

 everywhere in central and western Iowa. It grows abundantly 

 i 1 native prairie sod and along railroads. It is by no means 

 confined to the bottom land or the richer prairie soil, being 

 frequently found on sandy or gravely drift, but it affords more 

 and better forage on the richer soil. It is used for both hay 

 and pasturage, but it is of much less value as a pasture grass 

 than for hay. It has been tried in a small way under cultiva- 

 tion in central Iowa, with promising results. The trials have 

 not been extensive enough, however, to recommend it for 

 general culture. Shepard and Williams* state that it is "One 

 of the most valuable of our native grasses. It occurs through- 

 out the state (South Dakota) on dry and sandy as well as on 

 rich, moist soils, though it much prefers the latter sort." 



CHEMICAL, COMPOSITION. 



The following results were obtained from the sample ana- 

 lyzed in the experiment station laboratory : 

 NATURAL CONDITION. 



Collected September 11, '97 



beg 

 19.87 



WATER FREE SUBSTANCE. 

 Collected September 11. 1897 | 2.52 | 6 35 | (5.24) | 33.88 | 10.51 | 46.74 



The following analyses from other stations are given for 



comparison: 



NATURAL CONDITION. 



*Bull. South Dak. Agrl. Exp. Sta. 40:36. 



