Page and Bodman 161 



but no consistent or large increases have been obtained; in fact, in some 

 years there was a loss in yield where fertilizers were added. Table III 

 shows the average corn yields and gains from fertilizers in recent years. 

 It is significant to note that the natural fertility status of these soils is 

 high: yields as high as no bushels of corn have been obtained when 

 the season and the physical condition of the soil were both favorable. 



TABLE II 



Relative Average Unfertilized Corn Yields for Different Rotations 



(Paulding, Ohio) 

 (Actual 1936 Yield = 100 per cent) 



Rotations 1945 1942-1948 



per cent per cent 

 4 year (corn, oats, 2 yr. alfalfa or alfalfa-brome grass) 191 147 



3 year (corn, oats, alfalfa or sweet clover) 147 106 



2 year (corn, oats) 90 71 



Continuous corn 61 36 



Note: 1945 best corn year during period. Data before 1942 not used because rotations had not 

 been well established before that year (55). 



TABLE III 



Average Unfertilized Corn Yields and Response to Fertilizer Applications 



(Paulding, Ohio) 



Av. Gain 

 Yield for 



1945,1946, Fer- 



Rotations 1948 tilizer 



bu. bu. 



per acre per acre 



4 yr. (corn, oats, 2 yr. alfalfa or alfalfa-brome grass) 62.5 3.9 



3 yr. (corn, oats, alfalfa or sweet clover) 56 . 1 1.4 



2 yr. (corn, oats) 36.6 8.7 



Continuous corn 16.3 8.2 



Note: 1947 yields not included since yield data were not taken for fertilized vs. nonfei tilized 



plots. 



Fertilizer schedule: 150 lb. 0-20-20 /acre/yr. plus 300 lb. 20-0-0 before corn on last two 



rotations. 



^ # y 



