376 Agricultural Journal of Victoria. 



ANALYSES OF MANURES ON THE LOCAL MARKET. 



By F. J. Howell, Ph. D. 



In response to a circular letter sent out by tlie Director- to the 

 various Agricultural Societies in tlie Nortli, requesting that samples 

 of artificial manures should be collected from farmers and sent into 

 me for analysis, 40 samples reached the laboratory, and have received 

 attention. The Societies which responded to the invitation were the 

 Shepparton, Rochester, Murtoa, Kyneton, Nhill, Minyip, Rupanyup, 

 Tatiu-a, Yarrawonga, St. Arnaud and Donald. Nearly all the samples 

 sent in were superphosphates, and the results of the experiments of 

 this office, which clearly pointed to the marked superiority of the 

 water soluble form of phosphoric acid for the dry northern areas, 

 appear to have been widely recognised, and generally accepted as 

 correct by the northern wheat grower. 



The Quality of Manures on the Market. 



The superphosphates on the market appear generally to be of a 

 high standard, and with few exceptions gave as the result of analysis 

 figures equal to or exceeding those of the guaranteed percentages of 

 the invoice certificate. A serious cause of* complaint, however, is 

 the frequency with which manures appear to be sold in the country 

 without the prescribed guarantee. No comparison of the actual 

 contents of the manures with the represented composition has been 

 possible in a number of cases owing to this cause. In the case of 

 25 superphosphates, where the invoice certificates were available, the 

 results of analysis showed an actual average percentage of 17*10 per 

 cent, of water soluble, and 2*24 per cent, of citrate soluble phosphoric 

 acid. The average of the guaranteed percentages of these ingredients 

 in the 25 samples gave 16-35 per cent, water soluble and r07 per 

 cent, citrate soluble. That is, analysis showed the samples as an 

 average to be slightly better than represented. It was noticed, 

 however, in the course of analysis that the samples contained less 

 moisture than the samples sent in by manure merchants. Taking 

 the average of the 25 samples sent in there was a moisture content of 

 9-43 per cent, only, compared with 12-29 per cent, shown as an 

 average of 25 samples sent in by manure firms. In other words, the 

 superphosphate on the farm appears to have lost moisture, resulting 

 in analysis showing higher percentages of phosphoric acid than the 

 manures would have given with the original content of moisture. 

 Calculated on a moisture percentage of 12-29 per cent., the samples 

 would have shown, as an average, 16*56 per cent, of water soluble, 

 and 2-16 per cent, of citrate soluble phosphoric acid. These figures 

 are lower than the percentages actually found, but still above those 

 of the invoice certificates. 



