262 SOILS AND FERTILIZERS 



habits and food requirements. Barley is a stronger 

 feeding crop, has greater root development near the 

 surface, and can utilize food in cruder forms. In many 

 of the western states, soils which produce poor wheat 

 crops, from too long cultivation, give excellent yields of 

 barley. This is due to changed conditions, of both the 

 chemical and mechanical composition of the soil. Long 

 cultivation has made the soil porous, and reduced the 

 nitrogen content. Barley thrives best on a rather open 

 soil, and has greater nitrogen assimilative power than 

 wheat. Barley, however, responds liberally to manur- 

 ing, particularly to nitrogenous manures. The experi- 

 ments of Lawes and Gilbert on the growth of barley are 

 briefly summarized in the following table : 7Q 



AVERAGE YIELD OF BARLEY PER ACRE FOR 34 YEARS 



312. Oats. Oats can obtain food under more ad- 

 verse conditions than either barley or wheat. They are 

 also less exacting as to the physical condition of the 

 soil. The oat plant will adapt itself to either sandy or 

 clay soil, and will thrive in the presence of alkaline 



