1911. 



PUBLIC DOCUMENT — No. 31. 



43 



11, mixed grass 



rvc iilowed under), onions, onions, cabbages, coi 



and clover three years, cabbages and soy beans. The crop this 



year was potatoes. The results are shown in 



table : — 



Comparison of Phosphates. 



the following 



Plot. 



No phosphate, 

 Arkansas rock phosphate, 

 South Carolina rock, . 

 Florida soft rock, 

 Phosphatic slag, . 

 Tennessee phosphate. 

 No phosphate, . 

 Dissolved bone black, 

 Raw bone meal, . 

 Dissolved bone meal, . 

 Steamed bone meal, . 

 Acid phosphate, . 

 No phosphate. 



Yield 

 Merchant- 

 able 

 Potatoes 

 per Plot 

 (Pounds). 



2,148 

 2,170 

 1,986 

 1,761 

 1,841 

 1,773 

 1,831 

 1,859 

 1,941 

 1,982 

 1,964 

 1,929 

 1,610 



Yield 

 Merchant- 

 able 

 Potatoes 

 per Acre 

 (Bushels). 



Loss 

 or Gain 

 per Acre 

 (Bushels). 



The yield, as will be seen, was good on all plots. The aver- 

 age on the three check plots is 244.8 bushels of merchantable 

 ])otato€s per acre. It will be noticed that the only one of the 

 phosphates used which has given any very considerable increase 

 in merchantable potatoes is the Arkansas rock phosphate, but I 

 am con\'inccd that the superiority of this phosphate is more 

 apparent than real. The field declines somewhat in fertility 

 from Plot 1 to Plot I.']. It will be noticed that Plot 1 without 

 phos])hato gives a yield of merchantable tubers larger than any 

 of the phosphate plots, with the exception of two, and that the 

 crop on two is practically the same in amount as on one. The 

 superior yield on these two ])lois is in my judgment merely a 

 consequence of the fact that the soil texture in that part of the 

 field is; more favorable to the crop. The conclusions to which 

 I would e;dl particular attention may be stated as follows: — 

 (1) The potato would apj^ear to be a crop relatively inde- 



