The Bulletin 9 



They state tlie pounds of plant food in the surface six and two-thirds 

 inches, and in the subsoil twenty-eight inches of an acre: 



Pounds in Pounds in 



Surface 6H Subsoil 28 



inches inches 



I^Titrogen (N) 984 1,720 



Phosphoric Acid (P0O5) 1,236 2,200 



Potash (KoO) 3,810 13,200 



Lime (CaO) B,595 10,216 



Plats. 



The plats on which the experiments were conducted were embraced in 

 "Old" Field and in Fields A and B. The farm on which all the plats 

 are located has been in cultivation for a good many years. The experi- 

 ments were started for corn on ''Old" Field in 1903, on Field A in 1905, 

 and on Field B in 1906. The plats in Field A were laid off in three 

 parallel series of thirteen plats each with a turn row or drivcAvay be- 

 tween each series. The plats are one-tenth acre in size or 217.8 feet by 

 20 feet, with an unfertilized space between plats sufficient for one row 

 and a four-foot unfertilized space at the end of rows. Plats 1, 2 and 3 

 of the second series and 1, 2, 3, 4, 5, 6, 7, and 8 of the third series of this 

 field are somewhat inferior in natural fertility to the other plats of the 

 field, because of surface washing. 



The plats in "Old" Field and in Field B were laid out in a similar 

 way to those of Field A, except that the plats of the third series of Field 

 B were of one-twentieth acre in size, but in the other two series they 

 were of the same dimensions as those of Field A. Another difference 

 was that in Field B provision was made for two rows between the plats 

 instead of one as in Field A and in "Old" Field. These extra rows 

 were fertilized like the plats nearest to them, but were not harvested 

 and weighed with the plats. Work with cotton was started on Field B 

 in 1905. A rotation of cotton and corn on Field A was begun in this 

 same year. Bur clover was sown on Field B at the last cultivation of 

 corn in 1908 and of cotton in 1909, but as the clover failed in 1909,. 

 the plats were seeded to crimson clover early in November. The seed 

 were covered by a Planet, Jr., Cultivator, going once to the row. 



Field A.— The plats of this field were used for fertilizer experiments- 

 with cotton in 1903-04-06-08 ; and for fertilizer experiments with corn 

 in 1905-07-09. In case of each of these two crops, the same plan or 

 system of fertilization was followed. By this is meant that plat 8 in all 

 cases received only nitrogen and potash, plat 9 only phosphoric acid and 

 potash, plat 10 a normal application of nitrogen, phosphoric acid, and 

 potash and so on. The quantities and proportion actually applied, 

 however, varied with the two crops. The fertilization of the corn plats 

 Avas based on a normal application of 300 pounds per acre, of a mixture 

 containing 7 per cent available phosphoric acid, 3 per cent of nitrogen; 



