1909.] PUBLIC DOCUMENT — No. 31. 13 



field had been in grass for a nnml»Gr of years, and had been 

 used as a pasture. It would at that time produce about 30 to 

 40 bushels of shelled corn per acre, without manure or fer- 

 tilizer. 



Fertilizers used. — There has been a little variation in the 

 fertilizers applied to the plot in different years, but throughout 

 the greater portion of the time the actual application per acre 

 has been as follows : — 



Pounds. 



Nitrate of soda, 200 



Diy ground fish, 200 



Acid phosi^bate, 200 



Muriate of potash, ....... 250 



The market price of these fertilizers has varied somewhat 

 from year to year, but in the amounts used they have usually 

 cost from $15 to $18 per acre. 



The Corn Crops produced. — The yields of corn on this 

 plot, under the above system of management and fertilization, 

 have varied from 29.15 bushels of sound shelled grain per 

 acre in 1893 to 90.23 bushels per acre in 1908. The yield in 

 189^ was much below the yield in any other year. This was 

 due in a large measure to the ravages of wire worms. The 

 average yield for the twelve years has amounted to 55.8 bushels 

 of shelled grain and 5,189 pounds of well-dried stover per 

 acre. The first two corn crops, 1891 and 1892, averaged at 

 the rate of 56.3 bushels of shelled grain and 4,013 pounds of 

 stover per acre. The last two corn crops, 1907 and 1908, have 

 averaged 72 bushels of sound shelled grain and 8,057 pounds 

 of stover per acre. The crop of last year was the heaviest 

 that the field has ever produced. This was no doubt due to 

 the fact that the season was exceptionally favorable for the 

 crop. The fact that the average crop of the past two years is 

 considerably greater than the average for the first tw^o years 

 makes it apparent that the fertility of the field is not declining. 



Elements of Plant Food applied and reinoved. — A com- 

 parison of the total amounts of the leading plant food elements 

 applied to the soil and removed is of interest in connection 

 with the question as to what is the present condition of the soil, 

 as regards fertility, as compared with its condition at the time 



