18 FIELD CROP PRODUCTION 



of corn, corn, oats, and clover. Such results as these, 

 obtained on typical corn belt prairie soil of proverbial 

 fertility, furnish overwhelming evidence against the one 

 crop system. 



21. Rotation experiments in Ohio. — -Results from the 

 Ohio Station furnish much additional evidence on the 

 subject under discussion; they also throw light on 

 certain phases of the question with which the others 

 do not deal. In the experiments at each of the other 

 three stations the soil at the outset was in a good 

 state of productiveness, yielding without fertilization, 

 30 to 35 bushels of wheat or 70 to 80 bushels of corn. 

 At the Ohio Station, however, at the beginning of the 

 experiments the soil was in a badly run down condition. 

 It had been subjected for a half century or more to an 

 exhaustive system of farming. Also, this land in its 

 virgin state was not so productive as the prairie soils of 

 Iowa and Illinois and was less durable than the Rotham- 

 sted lands. Crop yields, therefore, being already reduced 

 to rather low figures, there has not been the opportunity 

 for further rapid reductions under continuous cropping. 

 However, on unfertilized land the average acre yields for 

 the last five of the 18 years show that continuous cropping 

 has reduced the yields as compared with the rotation in 

 use as follows : Corn from 26 down to 8 bushels per acre, 

 oats from 29 to 15 bushels, and wheat from 14 to 6 bushels. 



It is worth while to make a comparison of the two 

 systems under fertilizer treatment. There being no 

 plots in either of the two systems which have identical 

 fertilizer treatment, certain ones have been selected having 

 the same kind of treatment but in different amounts, and 

 the larger applications being on the continuous culture 

 plats. This makes the comparison all the more striking 



