156 MASS. EXPERIMENT STATION BULLETIN 162. 



Relative Profits on the Differerit Phosphates. 

 The results presented fully establish the facts of larger relative in- 

 creases and in some instances superior quality of crops on the more sol- 

 uble and available phosphates. Clearly, therefore, the use of such phos- 

 phates rather than the fine-ground natural rock phosphates is the part 

 of wisdom, unless the cost of the latter is so much lower that they allow 

 greater profit on their use than do the more soluble phosphates, in spite 

 of the greater crop increases on the latter. The table gives the differences 

 in value between the average annual crop increases and the average cost 

 for the different classes of phosphates. 



Gai7i or Loss per Acre in Crop Values covifpared with Cost of Phosphates. 



Natural 



Mineral 



Phosphates. 



Basic Slag 



AND Bone 



Meals. 



Dissolved 

 Phosphates. 



Cost of phosphates, . . . . . 



Corn, average of 3 crops, 1899, 1913, 1914: — 



Grain, 



Stover, ........ 



Total, 



Hay, average of 2 crops, 1906, 1907: — 



Hay 



Rowen, ....... 



Total 



Onions, average of 2 crops, 1901, 1902 (sound), 



Cabbage, average of 2 crops, 1903, 1908, . 



Oat hay, 1 crop, 1900, 



Hungarian hay, 1 crop, 1900, . . . . 

 Total, 



Ensilage corn, 1 crop, 1904, . . . . 



Soy beans, 1 crop, 1909: — 



Beans, 



Straw 



Total, 



Potatoes, 1 crop, 1910: — 



Merchantable, 



Small 



Total 



Oats and alfalfa, 1 crop, 1911, 



Alfalfa, 1 crop, 1911 



Total 



Annual average, . . . . . 



S3 67 



$3 70 



$3 24 



-$0 79 

 95 

 16 



3 19 



— 79 



2 40 



-15 30 



58 91 



1 39 



1 00 



2 39 



—6-55 



2 31 



87 



3 18 



—6 42 



48 



—5 94 



83 

 1 31 



S6 21 



$6 02 

 2 72 

 8 74 



4 92 

 58 



5 50 



71 80 



126 16 



7 95 

 —1 33 



6 62 



30 44 



12 27 

 2 38 

 14 65 



9 84 

 50 



10 34 



9 76 

 2 20 



11 96 



$36 23 



$34 57 



The results shown in this table are overwhelmingly conclusive on the 

 point under discussion. The values of the croi^ increases in all instances 

 exceed the cost of phosphate many times more on the more soluble and 

 available materials than on the natural rock phosphates. The latter 

 afford, therefore, far lower profits on their use than the former. 



