New YorkK AGRICULTURAL EXPERIMENT STATION. yey’ 
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. 
THER 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 freely during growth, 
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 as 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. 
