USE OF PHOSPHORUS IN DIFFERENT FORMS 297 



These figures show that the rock phosphate was applied at a dead loss of 

 $2.60 per acre the unfertilized yield value being $2.60 per acre more than the 

 rock phosphate. The yield with acid phosphate was $7.85 more than the 

 UNFERTILIZED, and $10.45 P er acre niore than the RAW ROCK PHOSPHATE. 

 These results are from experiments primarily intended to show the value of raw 

 rock as a fertilizer. They are self-explanatory, and show conclusively the FOLLY 

 OF CONSIDERING THIS MATERIAL AS A FERTILIZER. Further, these results were 

 obtained from 100 pounds of phosphoric acid in acid phosphate as compared 

 with 286 pounds of raw rock phosphate. 



The practical farmer, interested in the proper use of commercial fertilizers, 

 can easily figure that where acid phosphate gave such remarkable returns on 

 experiments covering a series of years, it will pay him a handsome profit to 

 invest judiciously in fertilizers every year giving such good returns. 



Tennessee has some of the largest phosphate deposits in the world. In this 

 state where the value of phosphate is so well understood, Professor C. A. 

 Mooers, chemist and agronomist of the Agricultural Experiment Station at 

 Knoxville, in a recent letter to THE AMERICAN FERTILIZER has the following to 

 say with regard to the use of this material in its crude state : 



"A bill was introduced in the Legislature, just adjourned, to allow the sale 

 of ground rock phosphate as a fertilizer. In presenting this matter to the 

 Agricultural Committee, the Commissioner of Agriculture and myself took the 

 position that it would not be desirable to tag this material, as that would, to a 

 certain extent, stamp it with the State's approval. Our position is better under- 

 stood when it is considered that a very large part of the fertilizers used in this 

 State are for wheat, and, as is well known, RAW PHOSPHATE ROCK, as ordinarily 

 used, GIVES NO RETURNS ON THIS CROP. Other large amounts are used, es- 

 pecially in West Tennessee, by the truckers, and for garden crops also RAW 

 PHOSPHATE WOULD BE INADVISABLE. Fertilizers have been used in this State 

 for many years, but our farmers have not studied the matter to any great ex- 

 tent, so that many of them would buy a fertilizer just BECAUSE IT WAS CHEAP, 

 especially if it had the State's tag on it. 



"Our results on leguminous crops, which are supposed to be better able to 

 make use of the so-called insoluble forms of phosphoric acid than others, do not 

 warrant the general use of RAW PHOSPHATE. I have recently corresponded 

 with a number of station men who are interested in the use of fertilizers, and I 

 find that the general opinion is AGAINST THE USE OF THIS MATERIAL, although 

 under special conditions, such as are found on a decidedly acid soil, its use may 

 be advisable." 



The state of Alabama is one of the oldest of the states using commercial 

 fertilizers. Bulletin No. 24, issued May 15, 1908, contains an article on "Raw 

 Phosphate Rock as a Fertilizer." Following are extracts from this article: 



"Many parties have written to this office for information as to the relative 

 fertilizing value of the raw phosphate, as compared with the acidulated phos- 

 phates, and the writer has invariably advised caution in the employment of this 

 particular kind of phosphate. 



