4 N. II. AC.K. EXPERIMENT STATION [ I'uUetiu 336 



In Table I are tabulated the grades of complete fer- 

 tilizers analyzed in this year's inspection, the number of 

 brands sampled by the inspector in each grade, the av- 

 erage per cent of nitrogen, of available prosphoric acid, 

 and of water soluble potash and the average retail price 

 per ton. 



CONFORMITY TO GUARANTEE 



Sixty-four of the 108 brands analyzed equalled or 

 exceeded the manufacturer's guarantee. No brand failed 

 to meet the guarantee in all of the three constituents, total 

 nitrogen, available phosphoric acid and water soluble 

 potash. Eight brands were below guarantee in two of the 

 three constituents, four in nitrogen and available phos- 

 phoric acid, and four in nitrogen and potash. Thirty-six 

 brands failed to meet the guarantee in only one con- 

 stituent. 



Including all the brands referred to above, 19 brands 

 were found to contain less than the guaranteed amount 

 of nitrogen. The greatest deficiency was 0.77 per cent. 

 The average of the other 18 deficiencies was 0.22 per 

 cent. Eleven brands failed to meet the guarantee in 

 available phosphoric acid. One brand was deficient 2,20 

 per cent. The average of the other 10 deficiencies was 

 0.54 per cent. Nineteen brands contained less potash 

 than was guaranteed. The greatest deficiency was 2.35 

 per cent. The average of the other 18 deficiencies was 

 0.70 per cent. 



Fifteen brands were guaranteed to contain magnesium 

 oxide. All fully met the guarantee. 



In the tabulation of the analyses in the following pages 

 deficiencies of one-fourth of one per cent or more are 

 shown in bold face type. The manufacturers are arranged 

 alphabetically. The brand name is listed alphabetically or 

 numerically by formula under the manufacturer. 



