1916.] PUBLIC DOCUMENT — No. 31. 55a 



merits of the station and by farmers. It has also found time to 

 conduct experiments to study values of different forms of plant 

 food. A brief outline follows: — 



(c) Other Activities of the Fertilizer Section. 



Forty-three brands of commercial fertilizers taken from the 

 1914 fertilizer inspection were washed out with warm water to 

 obtain a sufficient amount of water insoluble nitrogen for vege- 

 tation tests. These were made to study the activity of the in- 

 soluble nitrogen and to furnish a comparison with laboratory 

 methods. The water insoluble residues were subsequently an- 

 alyzed for their total nitrogen, as well as their nitrogen activity, 

 both by the alkaline and neutral permanganate methods. All 

 weights of fertilizing material made in preparation for the vege- 

 tation test (140 in number) were made in the laboratory. 



Four hundred and ninety-seven different substances have 

 been received and analyzed for farmers, farmers' organizations 

 and the various departments of the experiment station. The 

 materials may be classed as follows : — 



Fertilizers and by-products used as fertilizers, 178 



Lime products, 27 



Soils for lime requirement and organic matter tests, . . . .221 



Soils for complete analysis, 2 



Soils for partial analysis, 14 



Tobacco and onion soils suspected to be suffering from overfertiliza- 



tion, suspected of causing malnutrition of crops, .... 52 

 Greenhouse soils suspected to be suffering from overfertilization, 



suspected of causing malnutrition of crops, 3 



497 



Time has been found for considerable co-operative work with 

 the Association of Official Agricultural Chemists. Mr. Walker 

 served as referee on phosphoric acid for the year, planning the 

 work, preparing and sending out samples for analysis, and com- 

 piling the final report on this subject for the association. 



(d) Vegetation Tests. 

 A report of progress only can be made at this time on field 

 experiments begun in 1913 to study the availability of the phos- 

 phoric acid contained in basic slag phosphate. There are indi- 



