332 



PRINCIPLES OF AGRICULTURAL CHEMISTRY 



Examples of Fertilizer Experiments. The oldest and most 

 famous fertilizer experiments are those at Rothamsted, England. 

 Other important, long continued field experiments are those of 

 the Ohio Experiment Station at Wooster, the Rhode Island Ex- 

 periment Station, at Kingston, the Pennsylvania Experiment 

 Station at State College, and the North Carolina State Board of 

 Agriculture at Statesville, Red Springs, and Edgecombe, North 

 Carolina. 



Fig. 78. Experimental plot at the University of Nebraska. 



The Rothamsted experiments were begun in 1848, and are im- 

 portant not only for having been long continued under the same 

 plan, but also for the other valuable scientific studies made there. 

 The Rhode Island Experiments are most important for their bear- 

 ing upon soil acidity. The Ohio 1 experiments are very significant 

 as regards rotation and manure. 



The Rothamsted experiments comprise seven experimental 

 fields: (i) crops grown in rotation, (2) wheat continuously 

 1 Bulletins uo, 182, 183 and 184. Circular 120. 



