16 



CONTROL SERIES NO. 130 



POTASH COMPOUNDS 

 Muriate and High Grade Sulfate of Potash 



PULVERIZED ANIMAL MANURES 



In the following table the grade pf the manure is given with the brand name. 

 The grade is the guaranteed content of nitrogen, phosphoric acid and potash and 

 in that order. In some cases the phosphoric acid guarantee represents total phos- 

 phoric acid; in others, available phosphoric acid. Past experience has shown 

 that practically all of the total phosphoric acid is in available form. 



Since animal manures generally are purchased for qualities other than their 

 low nitrogen, phosphoric acid, and potash content that may be obtained much 

 more economically in other materials, the percentages given under the headings 

 "Organic Matter" and "Acid Insoluble Ash (Sand)" are highly significant. Some 

 samples of sheep manure analyzed by the Control Service have run as high as 

 60 percent sand and as low as 27 percent organic m.atter. If two samples of 

 sheep manure each contain about the same quantity of extraneous organic matter 

 such as bedding m^aterials, etc., it seems reasonable to assume that the sample 

 containing 60 percent sand has 35 percent less of those qualities so greatly prized 

 by some plant growers that they are willing to pay a high premium for them than 

 a sample containing 25 percent sand. Both lots probably would be sold at the 

 same price. 



The Association of Official Agricultural Chemists has this definition for dried 

 manures: "Dried, pulverized, or shredded manures are what the name indicates, 

 and not mixtures of manures and other materials." While it is realized that a 

 certain amount of sand and foreign organic material in animal manures is un- 

 avoidable, and that in sheep manures a higher sand content than in other animal 

 manures is to be expected, it would seem desirable to establish a maximum quan- 

 tity that an animal manure may contain. If the manure exceeded the sand con- 

 tent maximum it would be labeled "sheep manure-sand mixture." Any brand 

 containing over 50 percent sand would be labeled "sand-sheep manure mixture." 



