42 EXPERIMENT STATION. [Jan. 



rate of 17.7 per ceut. There was not a very wide difference 

 between the crops produced on the different phosphates, and the 

 most striking result of the experiment is the fact that the crop 

 where no phosphate has been applied during the past thirteen 

 years is nearly equal to the crops produced on the best of the 

 phosj^hate plots. On the same plots last year, cabbage being 

 the croj), the increase on the best phosphatic material of the 

 year, bone meal, was G67 per cent, of the average crop pro- 

 duced on the no-phosphate plots. These facts serve to empha- 

 size the point which I have previously many times referred to, 

 that in considering the plant-food requirements of soils it is 

 of the first importance that the crop be taken into consideration. 

 For the successful cultivation of the cabbage on this soil a 

 rapidly available form of phosphoric acid is essential ; but for 

 the soy bean, the application of phosphoric acid seems to have 

 been relatively unimportant. 



VI. The crop on the south corn acre, where manure at 

 the rate of 6 cords to the acre annually has been under com- 

 parison since 1890 with an application per acre at the rate of 

 4 cords of manure and 160 pounds of high-grade sulfate of pot- 

 ash, during the past year was hay, mixed timothy, red top and 

 clovers. The i:)lots to which the large applications of manure 

 alone have been made were materially larger than on the com- 

 bination of a lesser amount of manure and potash. The fol- 

 lowing are the average rates per acre: — 



Pounds. 



Manure alone : — 



Hay, 4,930 



Rowen, ......... 530 



Manure and potash : — 



Hay, . 3,670 



Rowen, 490 



The rowen crops of the past season were exceptionally small, 

 on account of a very marked deficiency in rainfall. It is 

 apparent, however, that although the combination of the lesser 

 amount of manure and potash substantially equals the larger 

 amount of manure for corn, which is grown in alternate two- 

 year rotations with hay, it is not equal for the production of hay. 



VII. On the north corn acre, where the combination of 

 fertilizer mat(a-ials rich in potash is under comparison with 



