1906.] PUBLIC DOCUMENT — No. 33. 29 



IV. — Special Fertilizer v. Fertilizer Richer in 



Potash. 



This experiment has been in progress since 1891. It 

 occupies an acre of ground, divided into four equal plots. 

 The crop from 1891 to 1896, inclusive, was corn ; in 1897 

 and 1898 the crop was mixed grass and clover ; in 1899 and 

 1900 it was corn; in 1901 and 1902, grass and clover; in 

 1903 and 1904, corn. The land was seeded in the corn in 

 late summer, 1904. The crop harvested this year is haj, — 

 mixed timothy, red-top and clover. The object in this ex- 

 periment is to test the question whether the special corn 

 fertilizers offered in our markets are of such composition as 

 is best suited for the i)roduction in rotation of corn and 

 mixed hay. The plots are numbered from 1 to 4. Plots 1 

 and 3 yearly receive an application of fertilizers furnisliing 

 the same amount of nitrogen, phosphoric acid and potash as 

 would be furnished by 1,800 pounds of fertilizer of the com- 

 position of the average 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 



Phosplioriu ;icid, . . . . . . . 10.00 



Potash, 4.30 



The fertilizers used on i)lots 2 and 4 are substantially the 

 same in amount and kind as recommended in Bulletin No. 58 

 of this station for corn on soils poor in organic matter. 

 The essential difference in composition between the fertilizer 

 mixtures under comparison is that the mixture used on 

 plots 2 and 4 is richer in j^otash and nmeh poorer in })hos- 

 phoric acid than the mixture representing the average market 

 corn fertilizers. The fertilizers applied to the several plots 

 are shown below : — 



