374 



GRASSES OF IOWA. 



breaking in order to restore the yield. " This spades should 

 not be generally cultivated in this state because of its weedy 

 character. It is a good grass for embankments, where it may 

 be used to advantage. 



CHEMICAL COMPOSITION. 



The chemical composition of Agropyron repens may be shown 

 by the following analyses made in the laboratory: 



Sample 1. Gathered April 18, 1896, height 4 to 8 inches. 



Sample 2. Gathered May 6, 1896, height 16 to 24 inches. 



Sample 3. Gathered May 20, 1896, height 20 to 30 inches. 



Sample 4. Gathered June 1, 1896, height 26 to 28 inches. 



Sample 5. Gathered .Tune 15, 1896, height 26 to 28 inches. 



NATURAL CONDITION. 



WATER FREE SUBSTANCE. 



Sample 1 . 

 Sample 2. 

 Sample 3. 

 Sample 4. 

 Sample 5. 



4.41 



3.86 

 7 37 

 6.08 

 6.59 



19.70 

 21.06 

 22 71 

 17.52 

 6 96 



(17 57) 

 (11.80) 

 (10.34) 

 ( 8.44) 

 ( 6 80) 



23.55 

 :i7.12 



24.28 

 27 56 

 25.97 



12.08 

 14.84 

 10 24 

 11.00 

 10.93 



40.26 

 33.12 

 35.40 

 37.84 

 49.55 



It will be noticed that the amount of water present is very 

 constant, ranging from 73.96 to 80.56 percent, and with one 

 exception the amount of water increases as the grass becomes 

 older. The fat present in the water free substance varies from 

 3.86 to 7.37 and there is no regularity regarding the amount 

 present in the samples. We find that the greatest amount of 

 crude protein is present in the sample collected on May 20, IBOf), 

 having a height of 20 to 30 inches. The amount of albuminoids, 

 however, is highest in the sample of April 18th, when 4 lo 8 

 inches high, and the amount decreases regularly as the grass 

 grows older until it is then only (>. 96 per cent in the last sample. 

 The crude fiber is quite constant and is not regular in its changes 

 during the growth, as shown by the analyses. The nitrogen 



