1184 



EARLE V. HAEDENBURG 



With the amount of seed used remaining constant, the yield was increased 

 in every instance by an increase in the value of manure and fertilizer used. 

 Furthermore, the yields were apparently sufficiently increased by the use 

 of fertilizer to the value of at least $40 an acre, to make such applications 

 profitable. It is evident that the maximum limit of fertilization in 1912 

 did not exceed the point of optimum profit. 



The correlation between value of manure and fertilizer, and yield per 

 acre, for this region is significantly expressed by the positive coefficient 

 0.244 d= 0.035 shown in figure 136. 



S 



Yield per acre, in bushels 



O <N O t^ O <> 



1 6 27 38 81 43 60 27 23 13 8 3 330 



r = 0.244 0.035 



FlG. 136. CORRELATION OF VALUE OF MANURE AND FERTILIZER, AND YIELD, ON 330 LONG 



ISLAND FARMS IN 1912 



Value of manure and fertilizer in Steuben County 



In Steuben County the value of manure and fertilizer has been studied 

 in a similar way. As appears in table 25, however, little manure and fertili- 

 zer is used here. Altho the average results indicate an increase in yield 

 from the use of as much as $50 worth of manure and fertilizer per acre, 

 the increased yield from applications of more than $20 worth per acre was 

 not sufficient to t cover the extra cost of the fertilizer. Therefore, in spite 

 of the relatively small amount of fertilizer applied in this region, there may 

 be other factors that limit the profit possible from larger applications. 

 The coefficient of correlation between this factor and yield, for this region, 

 is 0.289 0.033, as shown in figure 137. 



