104 BULLETIN 699, U. S. DEPARTMENT OF AGRICULTURE. 



the yields of all the soluble phosphate plots and was only surpassed 

 in actual yield by the plot treated with fine ground bone. Raw rock 

 also ranked among the highest of the unlimed plots, exceeding in 

 yield the plots treated with dissolved bone black, dissolved bone and 

 double superphosphate. 



During the third year of the second period, however, when mis- 

 cellaneous crops were grown the plots treated with the more available 

 and soluble phosphates showed to greater advantage. A point un- 

 favorable to the less soluble phosphates in this experiment is the fact 

 that many of the miscellaneous crops were cut and weighed before 

 maturity. Since acid phosphate undoubtedly gives greater early 

 stimulation than the raw phosphates, the effect of the former was 

 possibly more marked than it would have been had the crops been 

 allowed to mature. 



The results with soy beans during the fourth and last year of the 

 second period of the experiment were also more favorable to bone 

 meal, slag, and the soluble phosphates than to the ground raw rock, 

 both on the limed and unlimed series, but the floats gave greatly in- 

 creased yields over the no-phosphate plots. Large amounts of all 

 phosphates, except raw rock phosphate, were added this year, in 

 order to bring about the equalization of phosphate applications. It is 

 rather surprising, therefore, that the plots so treated should not have 

 given much greater increases for this year than the raw rock plots to 

 which nothing had been added since 1898. 



The third period of the experiment began in 1903, when 19 mis- 

 cellaneous crops were again grown across the plots in both series, a 

 few rows only being devoted to each crop. In 1904, oats were grown 

 and harvested as hay, and in 1905 and 1906, the field was in hay. 

 In 1907, miscellaneous crops were again planted across the plots. 

 Whitecap corn and a few rows of turnips were grown in 1908. In 

 1909, all the plots were planted in potatoes, which were followed by 

 rye. The rye was harvested in 1910, and Hungarian grass planted. 

 In 1911, oats were grown followed by rowen, and in 1912 and 1913 

 the field was again in hay. The yields obtained from the various 

 plots during this third period of the experiment are given in detail in 

 Table LXIV. 



