30 Maine Agricultural Experiment Station. 1918. 



Xo ammonia 5 plots* 101 hundredweight per acre 



Four per cent ammonia 5 plots 147 hundredweight per acre 



Eight per cent ammonia 4 plots 150 hundredweight per acre 



Twelve per cent ammonia 2 plots 152 hundredweight per acre 



Sixteen per cent ammonia 2 plots 160 hundredweight per acre 



Twenty per cent ammonia 1 plot 151 hundredweight per acre 

 *Omitting plot 39 



But as is discussed beyond (page 350), it would not do to 

 infer from this series of experiments a general proposition that 

 Caribou loam is deficient in ammonia. 



As phosphoric acid was not a limiting factor plot 21 in 

 which the phosphoric acid is in the form of floats would be ex- 

 pected to give as it did a yield as high as the same formula 

 with acid phosphate as the source of the phosphoric acid. Plot 

 44 in which the ammonia was in the form of tankage gave 

 results (155 cwt.) as would be expected. The low yields of 

 126 hundredweight from plots 28 and 29 may be due to soil 

 or subsoil differences. 



