70 The Buxletia-. 



bushels. In other words, it happens to be exactly the same, while they have 

 developed to the use of ^25,000.000 or $30,000,000 worth of fertilizers. My 

 guess is that if they would put this money into limestone and raw rock phos- 

 phate, finfely ground, plowed in with cowpeas, crimson clover, farm manure, 

 etc., the crop yield would be doubled in twenty years. 



In Maryland they have grown corn, wheat, and hay. At the same prices 

 mentioned before I find that the value of the increase in twelve years was 

 $27.20 where they invested $G.oO, as an average, in raw rock phosphate. 



Rhode Island has conducted investigations for eleven years and reported 

 results with ordinary raw rock phosphate and acid phosphate. A part of the 

 time they grew market garden crops on the land — beets, turnips, cabbage, cu- 

 cumbers, and squash — things accustomed to rich garden soils and that have but 

 little power to forage for themselves, and they received but little benefit from 

 the raw phosphate. But they grew during this time eight normal farm crops, 

 hay, and grain. The grain croits were harvested for hay, and the only way I 

 have been able to make a fair comparison is to reduce it to pounds per acre. 

 I find that on unlimed land whore raw rock phosphate was plowed in, the total 

 increase was 14,580 pounds. "Where acid ])hospbate was used in the same 

 quantity, the phosphorus costing three or four times as much, thoy got an 

 increase of 14,550 pounds. On the unlimed land the raw rock phosphate gave 

 slightly better returns than the acid phosphate; and on the limed land the acid 

 phosphate, costing four times as much, gave about one-fourth larger returns. 

 So far as money invested is concerned, the raw rock paid best. 



Phosphate should be finely ground. You can use limestone coarsely ground, 

 because there is no difiiculty whatever about the availability of limestone. 

 The great danger is loss of limestone, so It does not need to be finely ground. 

 But raw phosphate is not soluble; it is not lost by leaching; it is one of the 

 insoluble rocks. The seller should guarantee that at least 00 per cent of the 

 ground phosphate will pass through a sieve with 10,000 holes to the square 

 inch, or 100 meshes each way. Now. count that part of the phosphate which 

 will not go through the sieve as not worth the freight. 



The Maine Experiment Station has conducted investigations where equal 

 money values of raw rock phosphate and acid phosphate were used, and as an 

 average the raw rock phosphate gave larger increase in yields than the acid 

 phosphate did. but how large we do not know, because there was no plat 

 without phosphate, the comparison being made betwcH?n the two kinds. 



Over in Indiana they have reported four years work with acid phosphate 

 and raw rock. They put on 1,000 pounds of raw rock phosphate and 715 

 pounds of acid phosphate. They counted raw rock at $10 a ton and acid 

 phosphate at $14. With these amounts and the prices they figuretl that the 

 raw rock in four years gave them a net profit of $11.55 and the acid phosphate 

 gave them a profit of $13-50; but Dr. Goss, of the Indiana Station, says that 

 towards the end of the four years the raw rock gave very good results indeed, 

 even forging ahead of the acid phosphate. 



In Illinois we are using raw phosphate rock in about twenty different ex- 

 periment fields in different parts of the State. We are using it in the State by 

 thousands and thousands of tons : but our farmers understand that they must 

 make it available; that unless they plow it under with decaying vegetable 

 matter they will get nothing from it. The results I shall give you from Illi- 

 nois are those reported by one of our farmers. Frank I. Mann, farming 500 

 acres of land in the corn belt. He has covered his entire farm twice with 

 raw phosphate, except untreated strips where he does not put the phosphate. 

 He practices a four-year rotation — two crops of corn, oats, and clover. He 

 plows in the clover or feeds it and puts the manure back. He reports as an 

 average of five years that the phosphated land produces IG bushels more corn, 

 23 bushels more oats, and one ton more clover, per acre, than where phosphate 

 is not applied. Much more information regarding the use of different forms 

 of phosphorus can be secured from the publications of the Illinois Experiment 

 Station, such as circulars 127 and 149. 



I am sure that I ought not to take up any more of your time now. T thank 

 you for your attention. 



