139 



or beddins. and when the grain also is fed to animals practically all of the 

 potassium is rcrovered in the li(|uid and solid manure. 



If there is a sinjile key to America's permanent prosperity it is tlie element 

 phosphorus. 



I'hosphorus is the element of plant food which already limits the productive 

 rapacity of at least 80 per cent of our best agricultural soils, judging from all 

 available information. Fifty-one crops of corn yielding 100 Imshels of grain 

 and o tons of stover would retpiire the total phosphorus contained in our 

 average corn-belt soil to a depth of 7 inches. Three-fourths of tliis i)hospborus 

 remains in tlie grain, and thus leaves the farm if the grain is sold. If the grain 

 is fed to meat-producing or milk-producing animals, one-fourdi of the phos- 

 piiorus in tlie food con.sumed must leave the farm in the animal products, 

 butter alone excepted. 



How are we permanently to maintain in American soils a sufficient supply of 

 phosphorus to insure i)rofitabl(> crop yields? Is not this the greatest question 

 that now confronts the farmer or the exi)eriment station or the American 

 nation? 



We obtain phosphorus from basic slag in ex<-ellent form, but the total amount 

 of phosphatic slag produced oi- likely to be producinl in this country is almost 

 insignilicant compared with ])resent or future needs. 



The total supply of bone would be required to maintain the live-stock farms, 

 even if it were all returned to the land from whence it came; but at the pres- 

 ent time most of the bone produced in this country is used for other i)urposes 

 than to fertilize the land. Steamed bone meal, which contains one-third more 

 idiosphorus than raw bone and sells at a lower price per ton, is, however, one 

 of the most satisfactory forms of i)hosphorus for soil improvement. 



The natural rock phosphate deposits of the Fnited States, chiefly in South 

 Carolina, Florida, and Tennessee, are l)elieved to be among the most extensive 

 in the world. They. b)0. like the fertility of American soils, were once thought 

 tt> be inexhaustibh'. l)Ut now it is known that the visible supply of high-grade 

 lock will be exhausted in less than fifty years if the present rate of increase in 

 consumption continues. 



More than 1 .."><)( i.OoO tons of this phosphate rock are annually removed from 

 our deposits and more than 1,000,000 tons, or two-thirds of the entire product, 

 are annually exported to foreign countries. The phosphorus contained in this 

 annual export is sufficient for 1 ..500,(100.000 Imshels of corn, or half the annual 

 corn crop of the world. Is not this exportation America's greatest crime against 

 her own iwsterity? We can make l>ricks without straw but we can not grow 

 corn or wheat or cotton without phosphorus. 



And what is being done with the 500,000 tons of rock phosphate which is not 

 exported? A ton of this raw rock, containing say 2.")0 pounds of phosphorus 

 (sufficient for 1.500 bushels of com), which is worth about .$4 at the mine and 

 which can be delivered to Illinois farmers for about .$8, is commonly mixed 

 with a ton of sulphuric acid, thus making 2 tons of acid phosphate, containing 

 GO per cent of manufactured land plaster and only 125 pounds of phosphorus per 

 ton. The acid phosphate can be purchased by the farmer for $10 a ton, or 

 $30 for the same amount of phosphorus as is l)ought for .$8 in the raw state; 

 but as a rule 2 tons of acid phosphate are mixed with 2 tons of "filler" or 

 " make-weight," usually containing a small amount of nitrogen and potassium, 

 and thus we have 4 tons of so-called " complete fertilizer," the famous 2-8--2 

 goods,a containing 02* pounds of phosphorus per ton, and selling at retail in 



a By 2-8-2 goods is meant a " complete " fertilizer guaranteed to contain 2 

 per cent of ammonia, 8 per cent of " phosphoric acid," and 2 per cent of potasn, 

 or, on the basis of actual plant food elements, I9 per cent of nitrogen, 3^ per 

 cent of phosphorus, and If per cent of potassium. For a 100-bushel crop of corn 

 it would require 060 pounds of this fertilizer to supply the i)hosphorus, 4,300 

 pounds to supply the potassium, and 9,000 pounds to supply the nitrogen. 



One commercial fertilizer company advertises fourteen brands essentially of 

 this composition. This company advises farmers that " these brands will be 

 best on almost any soil," and especially recommends them for corn, oats, wheat, 

 and cotton. The average composition of these fourteen brands is as follows: 

 Nitrogen, 1.5 per cent; phosphorus, 8.9 per cent; and potassium, 1.3 per cent. 

 These amounts of nitrogen and potassium are too small to justify consideration 

 by the consumer. If the phosphorus is worth 10 cents a pound, the average 

 value of these fertilizers would be .$7.80 a ton, although the same amount of 

 phosphorus can be bought for $2.50. 



