60 BOARD OF AGRICULTURE. [Puh. Doc. 



men for askinoj for uniform les^islation relatins; to fertilizer 

 control. 



Again, the chemical side of the fertilizer control has 

 certain unfortunate weaknesses. In some particulars the 

 chemist's determinations are all that could be desired, but 

 in other directions he is subject to limitations which no one 

 regrets more than himself. It is now entirely possible to 

 accurately find out the total amount of nitrogen in a fer- 

 tilizer, but no method has been discovered, such as the 

 careful official is willing to make the ])asis of published 

 statements, by which to identify the low grades of organic 

 nitrogen. Let us hope that some method of this kind will 

 be forthcoming. 



I am free to confess, also, that the chemist is somewhat 

 lame in his estimation of the amount of available phosphoric 

 acid, if we use the term " available " as meaning that which 

 can be directly appropriated by plants. We have in the 

 market compounds of phosphoric acid that are counted as 

 available by the chemical methods now in vogue, which 

 are probabl}' used to reinforce the i)ercentage of the so- 

 called available phosphoric acid in mixed goods, but which 

 give in actual practice no certain promise of greater value 

 than we know crude South Carolina rock possesses. I 

 refer to certain dehydrated phosphates of iron and alu- 

 minum that have found their way into the fertilizer trade 

 within a comparatively recent time, liut which appear in 

 the experience so far reached to compare very unfavorably 

 with soluble phosphoric acid as food for such crops as pota- 

 toes, corn and other grains. We cannot now reasonably 

 claim that we are able to find out by artificial means just 

 what compounds of phosphoric acid the plant can promptly 

 feed upon, excepting, of course, those which are solul)le in 

 water previous to their application to the soil. 



The fertilizer dealer has had the unique experience of 

 having his goods made the subject of comparative money 

 valuations. Some official chemists have undertaken to 

 state the cash sum at which the ingredients of particular 

 fertilizers could be bought after deductino; certain ex- 

 penses. No State law has required this, but it has been 

 done for the purpose of rendering more useful the results 



