68 The Bulletin. 



though the increase in the crops more than pays the cost, it is not the final 

 test of the work. I know that a good many people say that is all they want. 

 Even if the increase in the cotton crop will more than pay the cost of the nitro- 

 gen — and as a rule it will, because cotton sells at 12 to 15 cents per pound, while 

 corn sells for 1 cent per pound — even that does not always justify buying nitro- 

 gen. The question is, Which is the most economical way? Instead of buying 

 nitrogen at $2 an acre, you may get it for 50 cents by growing leguminous 

 crops. We get nitrogen from the air with this vegetable matter. We liberate 

 potash from an inexhaustible supply in almost all normal soils by decaying 

 vegetable matter. On any soils where you are using a complete fertilizer you 

 have already 30,000 pounds of potash, and you can set it free by decaying 

 vegetable matter. Then you can use a fine-ground raw rock phosphate and 

 plow it under with the decaying vegetable matter, and as it decays it will 

 liberate the phosphorus. Did you ever lose a pitchfork and find it six mouths 

 afterwards in a manure pile? The tines are almost gone. This illustrates the 

 power of decaying vegetable matter — it dissolves steel, and it will dissolve 

 phosphate also. 



Decaying vegetable matter furnishes nitrates also for growing crops. Nitro- 

 gen must pass througli the form of nitric acid to get to nitrates. If you 

 furnish the nitrogen by plowing in vegetable matter for a certain crop, such as 

 corn, then the amount of nitric acid that would be produced when the nitrogen 

 is changed from organic matter to nitrates would be seven times as much as 

 you need to dissolve the phosphate required for the same crop. Now, do not 

 understand that the nitric acid will act solely upon the phosphate. Some of it 

 will act upon lime compounds, some in dissolving silicates. But in addition 

 to nitric acid, when organic matter decays it forms organic acids, and they, 

 too, have power to dissolve phosphates. The ultimate product of all carbon 

 decay is carbonic acid, and that also has some power to dissolve some of these 

 substances. Now, whether you will use this decaying vegetable matter to 

 manufacture the fertilizer out of the potash already there and out of the raw 

 rock phosphate you can apply, or whether you will have the manufacturer put 

 it through his factory, you will have to decide. The fertilizer manufacturer 

 can take two tons of acid phosphate, made of one ton of raw phosphate and 

 one ton of sulphuric acid, and he can mix with that some nitrogen and potas- 

 sium and filler, and make four tons of complete fertilizer that sells at about 

 $20 per ton. How much would it cost to get complete fertilizer enough to 

 carry the same amount of phosphorus that you get for about $7.50 in one ton 

 of raw rock? How much would it cost to buy that phosphorus, the same 

 quantity, in complete fertilizer? It would cost $75 or $80. 



In order to emphasize the fact that 5'ou cannot build up the productive 

 power of your land simply by putting on raw rock phosphate, I am going to tell 

 you of an experiment conducted by the New Jersey Experiment Station two or 

 three years ago. They took some quartz sand, added some limestone or cal- 

 cium carbonate and magnesium, which is equal to dolomite, and then added 

 some kainit and some chlorine and some sulphur and some sodium nitrate 

 and a little iron sulphate, but not any phosphorus. Then they planted rye in 

 the jar. Now, I want to call your attention to the fact that of all farm 

 crops, rye is least able to get phosphorus from the raw form. They dried the 

 crop and weighed it. It weighed .36 gram. Now, right beside that they had 

 another jar in which they put two grams of acid phosphate, and the yield of 

 rye was 6.36 grams. They had a yield of 636 instead of 36. Now, In another 

 pot beside that they put two grams of raw rock, and the yield was .41 gram. 

 They then put in 4 grams of raw rock phosphate and got .39 gram of rye. 

 They put in 20 grams of this fine-ground raw rock phosphate, and thei-e the 

 yield was .36, exactly the same as where no phosphate was added. What do 

 these data teach? They teach that when you put fine-ground phosphate in 

 quartz sand and grow rye, you do not get anything out of the process. Similar 

 experiments have been tried for fifty years. They teach that raw phosphate is 

 not available. The statement is made regarding this New Jersey experiment 

 that the soil was devoid of humus— there was no vegetable matter in it, but 

 that the enormous quantities of raw phosphate employed should have fur- 

 nished at least some available phosphorus for plants. I sometimes say that 

 the investigator in the agricultural experiment station should publish the data 



