ORGANIZATION AND MANAGEMENT OF FARMS IN PENNSYLVANIA. 



29 



Acid phosphate was used by many farmers. Some, however, used 

 more expensive fertilizers. Mixing acid phosphate with stable 

 manure in the barn was not practiced to any extent. 



In order to show the effect upon crop yields of increasing the 

 amount of fertilizer and manure used per 100 acres of crops, the 

 349 farms were grouped as shown in Table XV. 



Table XV. — The effect upon crop yields of applying different amounts of fertilizer and 

 of live stock kept on 349 farms, Grove City, Pa., area. 





Fertilizer per acre. 



Animal units per 100 



None. 



100 pounds or under. 



Over 100 pounds. 



acres of crops. 



Animal 

 units per 

 100 acres 

 of crops. 



Fertil- 

 izer per 

 acre. 



Crop in- 

 dex. 



Animal 

 units per 

 100 acres 

 of crops. 



Fertil- 

 izer per 

 acre. 



Crop in- 

 dex. 



Animal 

 units per 

 100 acres 

 of crops. 



Fertil- 

 izer per 

 acre. 



Crop 

 index. 





25 

 43 



Pounds. 

 

 



82 

 100 



28 

 45 



Pounds. 

 55 

 63 



92 

 107 



28 

 44 



Pounds. 

 174 

 160 



98 



Over 35 



109 







Farmers using over 100 pounds of fertilizer per acre of crops and 

 keeping less than 35 animal units per 100 acres of crops failed to pro- 

 duce as high crop yields as the farmers who used no fertilizer but had 



Fig. 8.— Limestone prepared for burning. Either coal or wood may be used. 



over 35 (or an average of 43) animal units per 100 acres of crops. 

 The highest crop yields were obtained by the group using over 100 

 pounds of fertilizer per acre and keeping over 35 animal units per 100 

 acres of crops. The crop yields on these farms were 9 per cent above 

 the average of all the farms. The lowest crop yields were on the group 



