/p/o] CARBON, PHOSPHORUS AND NITROGEN IN SOILS 101 



Aso (58) confirmed, in a general way, the results obtained by 

 Schmoeger. He also found 0.049 percent of lecithin in the soil. 

 He drew the following conclusions : 



1. Phosphorus existed in the soil as inorganic and organic 

 compounds. 



2. The organic phosphorus material was principally nuclein 

 with a very small part of lecithin. 



3. Ignition rendered the phosphorus in organic combination 

 available. 



Hartwell and Kellogg (60) found that an average of one-half 

 of the phosphorus was associated with the organic matter in the 

 soil taken from four plots which had received different treatment. 



Dumont (62) studied a complete manure, the composition of 

 which was as follows: solnble matter (in dilute alkali) 50.4 per- 

 cent; insoluble matter 49.6 percent; total nitrogen 1.6 percent; 

 total phosphorus 1.27 percent. 



The soluble portion contained 35 percent of the nitrogen and 

 46 percent of the phosphorus. In order to obtain data upon the 

 state of combination of the phosphorus, the ammoniacal solution 

 of mailer e noire was treated with various reagents with the result 

 (recalculated to the element basis) shown in Table 4. 



TA.BI,E 4. DISTRIBUTION OF PHOSPHORUS WHEN MATIERE NOIRE is 

 PRECIPITATED 



These results furnished conclusive proof to Dumont that a part 

 of the phosphorus of the soil was in organic combination. 



Later (64) he obtained better cultural results from application 

 of humic phosphatic manures than from mineral phosphatic ma- 

 nures and better even than from barnyard manure, which he at- 

 tributed to the phosphorus in organic combination. 



In a still later article (65) he said that the organic phosphorus 

 was derived from two sources : first, from the nuclein and lecithin 

 of the decaying vegetable and animal debris ; second from the 

 union of the humus with the water soluble phosphates of the soil. 



Evidence of the latter contention was obtained by precipitating 

 the matiere noire in the presence of potassium hydrogen phosphate 

 by different reagents as indicated in Table 5. 



