1905.] PUBLIC DOCUMENT — No. 33. 141 



nual reports. The object in view is to test the question as to 

 whether the special corn fertilizers offered in our markets are 

 of such composition as is best suited for the production of 

 corn in rotation with mixed grass and clover. The field used 

 in the experiment contains one acre, and is divided into four 

 equal plots. Plots I and 3 have yearly received an ap[)li- 

 oation of mixed fertilizers, furnishing the same amount of 

 nitrogen, phosphoric acid and potash as would be furnished 

 by 1,800 pounds of fertilizer of the composition of the aver- 

 age of the special corn fertilizers analyzed at this station. 

 This average has changed but little during recent years, and 

 in 1899, since which date we have made no change in the 

 kinds and amounts of fertilizers used, was as follows : — 



Per Cent. 

 Nitrogen, ......... 2.37 



Phosplioric acid, . . . . . . .10.00 



Potash, 4-30 



The various fertilizers offered in 1899 differed widely in 

 composition. The extent of the variation is shown in the 

 following table : — 



Per Cent. 

 Nitrogen, ........ 1.5- 3.7 



Phosphoric acid, ....... 9.0-13.0 



Potash, 1.5-9.5 



The fertilizers used on plots 2 and 4 are substantially the 

 same in kind and amount as recommended in Bulletin No. 

 58 for corn on soils poor in organic matter. The essential 

 difference in composition between the fertilizer mixtures un- 

 der comparison is that that used on plots 2 and 4 is richer 

 in potash and much poorer in phosphoric acid than the mix- 

 ture representing the average market corn fertilizers. The 

 fertilizers applied to the several plots are shown below : — 



Fertilizers used. 



Plots 1 and 3 

 (Pounds Each) . 



Plots 2 and 4 

 (Pounds Each). 



Nitrate of soda, 

 Dried lilood. 

 Dry irroiiiid lisli, 

 Acid jiliiispliate. 

 Muriate of iiotash, 



30.0 

 30.0 

 37.. 5 

 273.0 

 37.5 



50.0 

 50.0 

 62.5 



