November, 1925] fertilizer inspection, 1925 7 



protect himself against unwarranted dift'erences in retail 

 prices by figuring for himself the commercial value of a 

 fertilizer before he agrees to purchase it. 



NATURAL MANURES. 



The statement is often made by consumers that commer- 

 cial fertilizers are not so good as the natural manures. This 

 statement may or may not be true, depending upon the 

 grades of manures and the grades of commercial fertil- 

 izers that are being compared. When purchase is con- 

 templated, no comparison between natural manures and 

 commercial fertilizers is to be relied upon which does not 

 take into consideration the relative price per ton or per 

 pound of the available plant food materials. Within the 

 past year several hundred tons of five different brands of 

 sheep manure were shipped into the state and sold at an 

 average price of $52.40 per ton. The average analysis of 

 the five brands was nitrogen 2.17 per cent, available phos- 

 phoric acid 1.29 per c»nt and water soluble potash 2.39 

 per cent. Figuring the value of these sheep manures on 

 the basis of the cost of nitrogen in equal parts nitrate of 

 soda and tankage, of phosphoric acid in acid phosphate 

 and of potash in muriate of potash the average value was 

 $17.96 per ton. The cost to the consumer of the sheep 

 manure sold in the state during the past year was about 

 three times its commercial value. 



NUMBER OF SAMPLES FOUND DEFICIENT. 



Of the 113 samples analyzed 1 was found deficient by 

 0.2 per cent or more in all three elements, 4 were deficient 

 in two elements and 13 in one element. A deficiency of 0.2 

 per cent of nitrogen amounts to about $1.25 per ton. The 

 total number deficient was 16 per cent of the samples 

 analyzed. This shows some improvement over 1924, 

 when 21 per cent were deficient. In 1923 there were also 

 21 per cent deficient. In the tabulation of the analyses in 

 the following pages deficiencies of 0.2 per cent or more are 



