CARBONATE OF LIME. 135 



and Germany. Our own iron ores, being poorer in 

 phosphorus, do not make much of this substance. 

 It is in great use in the Old World. Germany alone 

 uses 2,000,000 tons of it each year. Wherever tested 

 in America it seems to give very satisfactory re- 

 sults. The writer tested it on Woodland Farm many 

 years ago and never got stronger, healthier alfalfa 

 than by its use. 



Basic slag usually contains from 16 to 20 per cent, 

 of phosphoric acid with from 36 to 50 per cent, of 

 lime. It is said that the phosphoric acid is in 

 a form that is nearly all available, and it can- 

 not revert in the soil nor leach away. There is 

 hardly a farm east of the Missouri river where 

 more phosphorus will not yield profit. Where 

 freights are not too high, basic slag costs no more 

 for the available phosphoric acid than any other 

 source of phosphorus, and thus the lime is gotten 

 free. It is advised that from 1,200 to 1,500 pounds 

 per acre of basic slag be applied where alfalfa is 

 sown. The large surplus of phosphorus thus given 

 will not leach away, but will remain to feed the 

 plants for some years, while the lime will help 

 sweeten the soil. 



Basic slag costs too much for use at present in the 

 combelt states. Where it is available is in New 

 England, New York, and along the Atlantic sea- 

 board. The price is about one dollar per unit of 

 phosphoric acid ; that is, slag analyzing 17 per cent, 

 available phosphoric acid would cost the consumer 

 about $17 per ton. At present writing the Coe- 



