New York Agricultural Experiment Station. 



121 



ALL AVAILABLE TO PLANTS IN THE SOIL. 



The above are the Lowest and the Average Analyses." 

 This guaranteed analysis is misleading in the following par- 

 ticulars : 



(1) It guarantees to be present constituents which have no 

 market value as fertilizers, such as silicic acid, carbonic acid, 

 etc., leading the average farmer to believe that these constit- 

 uents are as valuable as potash and phosphoric acid. 



(2) It states that the total phosphoric acid is equal to 47.20 to 

 64.38 per cent of bone phosphate of lime. This statement is made 

 for the specific purpose of representing to farmers that the phos- 

 phoric acid is as good as the phosphoric acid contained in bone. 



(3) It states that the potash present is from glauconite, the 

 latter in very small type, and adds that it is "equal to common 

 sulphate of potash." Potash in glauconite is very slowly avail- 

 able, while in sulphate of potash it is readily and completely 

 available. 



(4) Beneath the guarantee statement appears in capital let- 

 ters, " all available to plants in the soil." How misleading this 

 assertion is, we can show by the results of our analysis, coupled 

 with experimental work done elsewhere. 



3. Analyses of '' Natural Plant Food " at this Station. 



Our collecting agents secured in May and June three samples, 

 one each in Fayetteville, Gouverneur and Saratoga Springs. 

 The results of analysis are as follows: 



SAMPLE. 



Number 1 . . 

 Number 2 .. 

 Nuuiber 3 .. 



Average 



Pounds of Phosphoric Acid in 100 

 Pounds of N. P. F. 



Available Insoluble. 



2.22 

 0.93 

 1.06 



1.40 



23.87 

 19.60 

 18.96 



20 81 



Total. 



26.09 

 20.53 

 20.02 



22.21 



Pounds of 

 potash sol- 

 uble in 

 water in 100 

 pounds of 

 N. P. F. 



0.11 

 0.12 

 0.17 



0.13 



