GRASSES 203 



hindered in the presence of as much as 5000 parts per mil- 

 lion of white alkali and to make a good growth and pro- 

 duce seed with 7000 parts per million. In California (20) 

 it was unaffected with 3170 parts per million of total salts, 

 630 parts per million of sodium carbonate, 230 parts per 

 million of sodium chloride, or 2230 parts per million of 

 sodium sulphate. This is one of the best pasture grasses 

 of the western part of the United States where the land is 

 not kept too wet. 



Red top (Agrostis alba) has not been tried extensively 

 under alkali conditions but Kearney (17) reports it to 

 succeed in the presence of 4000 to 6000 parts per million 

 of white alkali and to do better than timothy or orchard 

 grass. It grows well on excessively wet lands, lands too 

 wet for even timothy, and in such land can probably 

 withstand as much alkali as any of the important culti- 

 vated grasses. 



Bluegrass (Poa pratensis). In California bluegrass 

 withstood successfully 670 parts per million of total salts, 

 380 parts per million sodium carbonate, and 220 parts 

 per million of sodium sulphate. It is ordinarily regarded 

 as very sensitive to alkali and this apparently shows 

 it to be one of the most tender tame grasses. In rather 

 extensive tests made by Harris and Pittman (7) it was 

 found to be the most nonresistant crop under investigation. 



Western wheat grass (Agropyron) may be regarded as one 

 of the most resistant grasses, as it can be grown success- 

 fully upon soil containing at least 6000 and 8000 parts 

 per million. It is very difficult to get started because of 

 low germination of the seed. The lack of popularity is 

 partly due to this difficulty of getting a start. 



Japanese wheat grass (Agropyron japonicum) was found 

 by Loughridge in California (20) in the presence of 2330 



