106 BULLETIN 699, U. S. DEPARTMENT OF AGEICULTURE. 



Considering the results obtained during the third period of the 

 experiment the yields of miscellaneous crops in 1903 were on the 

 whole considerably greater on the soluble-phosphate plots and those 

 treated with basic slag and ground bone than on the raw rock phos- 

 phate plots. 



In 1904 the raw-rock plots (limed and unlimed) gave smaller 

 yields of oat hay than any of the soluble-phosphate plots, with the 

 exception of double acid phosphate (unlimed.) The yields of hay 

 from the raw-rock plots, however, in 1905 and 1906 compared quite 

 favorably with those of the other phosphate plots. 



The yields of most of the miscellaneous crops grown in 1907 were 

 greater on the soluble phosphate, bone, and basic-slag plots than on 

 those treated with raw rock phosphate, but the average yield ob- 

 tained on plots treated with the latter material were very much 

 greater than those of the check plots. 



In 1908 the yield of whitecap corn from the raw-rock plot 

 (unlimed) was greater than that from any of the soluble-phosphate 

 plots, but did not equal the yields of the ground-bone and basic-slag 

 plots. On the limed series, however, the yields of corn were greater 

 on the basic-slag, bone, and soluble-phosphate plots. The results with 

 the few rows of turnips grown this same year ' on the limed series 

 were more favorable to raw rock phosphate than to any other phos- 

 phate application, but on the unlimed series basic-slag treatment 

 showed to much greater advantage. 



In 1909 the yield of potatoes from the raw-rock plot (limed 

 and unlimed) was exceeded by all the other phosphate plots except 

 raw Eedonda, dissolved bone black (unlimed) and double super- 

 phosphate (unlimed). The rye which was planted in 1909 and 

 harvested in 1910 gave considerably better yields on the plots (limed 

 and unlimed) treated with slag, bone, and the soluble phosphates 

 than on the raw-phosphate plots. The same was true of Hungarian 

 hay which followed rye. In 1911, however, the yields of oats on 

 the raw-rock plots compared very favorably with the yields from 

 the plots which had received equal amounts of phosphoric acid in 

 other forms. The hay crops in 1912 and 1913 were somewhat better 

 on the slag, bone, and soluble-phosphate plots than on those treated 

 with raw rock, but the yields of turnips this same year from the 

 raw-rock plots compared favorably with those from the plots receiv- 

 ing other phosphates, except dissolved bone black and basic slag 

 (unlimed). 



In summing up the results of this long-time experiment it can be 

 said that distinct increases in yields were obtained from the use of 

 raw rock phosphate. In nearly every case where this material was 

 applied in quantities supplying from two to three times as much 

 phosphoric acid as acid phosphate it compared favorably with the 



