New Yokk Agricultural Experiment Station. 227 



must be due to its greater proportion of phosphoric acid, even 

 though both mixtures supplied this ingredient in large excess 

 above the needs of the crop. This leads to the observation that 

 we are still much in the dark concerning the recoverableness of 

 the compounds which we apply to the soil in fertilizers. 



THE NECESSARY AMOUNT OF POTASH IN GROWING POTATOES. 



In some way farmers have come to believe that the potato 

 plant demands heavy feeding with potash. This view has found 

 expression in the so-called " potato fertilizers " which are offered 

 to potato growers in great variety of-name and composition, the 

 characteristic feature of which is their high percentage of potash. 

 Just how rational this common notion is, is a matter of doubt. 

 Potatoes are not alone in utilizing potash freeJy during growt|i, 

 and its probable that this crop is not greatly unlike many others, 

 including roots and forage crops, in its fertilizer requirements 

 under given conditions. 



Some years ago, many farmers on Long Island came to regard 

 a generous use of potash ae advisable in potato culture, and the 

 4, 8 and 10 formula was adopted. On what experimental data 

 this conclusion rested, the writer is not informed. 



In 1898 experiments touching this point were begun on the 

 four farms mentioned and the same method of treatment has 

 been continued on the same plats for three years. The results 

 are summarized in Table XIII. 



