224 Report on Crop Propuction or THB 
DISCUSSION OF RESULTS. 
The data from these experiments, which have been very fully 
given in this and previous bulletins, bear upon three main points 
which are important to Long Island potato growers, or those 
producing potatoes under similar conditions: (1) The relation to 
profit of the quantity of fertilizer applied; (2) the most desirable 
mixture of fertilizing ingredients, with especial reference to (3) 
the necessary amount of potash. 
THE QUANTITY OF FERTILIZER. 
For profit—The experiments conducted by Dr. Van Slyke in 
1895 and 1896 led to the conclusion that “the use of over 1,000 
pounds of fertilizer an acre under the conditions tried was 
attended with loss, as compared with the results obtained in 
using 1,000 pounds of fertilizer.” 
The results from 1897 to 1900 inclusive are summarized in the 
following table: — 
TABLE IX.—INCREASE OF YIELD OF POTATOES FROM DIFFERENT QUANTITIES 
OF FERTILIZER, FOUR YEARS. 
Amount INCREASE* INCREASE _ INCREASE INCREASE AVERAGE 
o 1897. 1898. 1899. 1900. INCREASE. 
fertilizer ——~-—~4  =-———~ —~ ; N roo —s 
per acre. Large. Total. Large. Total. Large. Total. Large. Total. Large. Total. 
_ Lbs. Bu. Bu. Bu. Bu. Bu. Bu. Bu. Bu. Bu. Bu. 
500> + 3421+31.6 °33.2. 338.4 38.4 °9:7 15.2 18.582) beeeeee 
1000. 69.1 62.3 61.8 60.7 18.6 20.3 30.2 383.5 43.7 44.2 
1500 77.5. 65.1° 85.8) 84.8 15:9 23.3. 44.2 45g. a5 Seon 
2000. .78.%.»,71.38 ,89.9. 89.7 25.6 36.0 44.8 48.6) 59.7" 61-4 
*Average of Fleet and Hallock plats. 

It is very evident that the increase in yield is not proportional 
to the quantity of fertilizer applied. As an average for four 
years, the first 500 lbs. caused an increased yield of 23.5 bushels; 
_ the second 500 Ibs., 21.9 bushels; the third 500 lbs., 11.2 bushels; 
and the fourth 500 Ibs., 6 bushels. . The fertilizer (L. I, Formulas) 
cost about $25.00 per ton. If we assume that the potatoes were 
worth 50 cents per bushel we have the balances as shown below. 
