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Indiana University Studies 



ton. The Indiana railroad commission has fixed the rates on 

 natural fertilizer, such as crushed limestone, at a very low figure, 

 in most cases not over 70 to 80 cents per ton. 



For lands known to be lacking in potassium, gypsum could 

 be mixed with the fertilizer. The average cost of gypsum in 

 this countiy last year (1913), was, according to the report of the 

 Bureau of Mineral Resources, about $2 per ton, and the amount 

 used on land as fertilizer was about 55,000 tons. The three could 

 be mixed as follows for land deficient in potassium: four parts of 

 crushed limestone, two parts of phosphate rock, and one part of 

 gypsum. This mixture could be put on the market at the same 

 price as that mentioned above. Deposits of gypsum occur in 

 large quantities in Northern Ohio, and the cost at this point would 

 undoubtedly be considerably lower than the S2 per ton mentioned 

 above. 



The total output of phosphate rock from the Tennessee fields 

 was approximately 450,000 tons last j^ear (1913), which rep- 

 resents about 14.5 per cent of the total output of the United 

 States. The deposits are very large, and this valuable mineral 

 fertilizer should have a much broader use in the treatment of 

 worn-out soils than it has at the present time. The use of 

 crushed limestone in the treatment of acid soils has increased 

 so rapidly that the figures given for any one year are far below 

 those of the next 3- ear. The latest figures available are 200.000 

 tons for the year 1912. 



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