ILLINOIS FIELD EXPERIMENTS 



475 



TABLE 93. CROP YIELDS IN ILLINOIS SOIL EXPERIMENTS: MOMENCE FIELD 



chemical substances injurious to agricultural plants or to necessary 

 bacterial life, which may be corrected or destroyed by potassium 

 salts or other materials; and the recent very extensive investi- 

 gations by the United States Bureau of Soils indicate that condi- 

 tions may be brought about, artificially at least, in which organic 

 toxic substances develop that are injurious to plant growth. 



