MAINE AGRICULTURAL EXPERIMENT STATION. I913. 35 



FERTILIZER INSPECTION. 



Four hundred and eighty-seven samples of fertiHzing ma- 

 terials were received and analyzed in the last inspection. 

 Nearly all of these were mixed fertilizer, only 19 samples of 

 chemicals being received. These consisted of 6 samples of 

 nitrate of soda, 5 samples of acid phosphate, and 7 samples of 

 muriate and sulphate of potash. 



In addition to the regular determinations of nitrogen, phos- 

 phoric acid and potash the quality of the nitrogen in the mixed 

 fertilizers was determined. This work involved four extra 

 determinations of nitrogen and increased the work of analyzing 

 a fertilizer about one-third. It is of value, however, in detect- 

 ing low grade forms of nitrogen which are often used in low 

 grade fertilizers. 



The mineral nitrogen, particularly that in the form of nitrate, 

 is very important to Maine farmers, especially those growing 

 potatoes, and the nitrate content should be considered as much 

 as the total nitrogen. 



Manufacturers are still in some instances using very different 

 sources of nitrogen in the same brand of fertilizer. It certain- 

 ly does not seem to be unreasonable to insist that a high priced 

 and high grade brand of fertilizer be as uniform in the forms 

 of nitrogen that it carries as in its total nitrogen. For instance, 

 it is believed to be necessary in this climate for the best re- 

 sults that a potato fertilizer contain about one-third of its 

 nitrogen as nitrate. If much more is present it is liable to loss 

 from leaching. If much less is present the plant will not have 

 enough immediately available nitrogen. Most of the manu- 

 facturers do not appear to attach sufficient importance to this 

 feature. They frequently substitute ammonium sulphate or 

 organic nitrogen for nitrate nitrogen, seeming to have only the 

 total nitrogen in mind. 



Even a cursory examination of the tables in Official In- 

 spections 53 will show figures that bear out the above state- 

 ment. This is as true of the high as of the low priced brands 

 of fertilizers sold in the state. And also it seems to apply to 

 a large number of the makers. It would seem that one should 

 have the right to expect that the goods would be uniformly 

 made and mixed. The variations in character of the nitrogen 

 content seem to indicate that too little importance is attached by 



