.12 CONTROL SERIES No. 51 



Muriate of Potash (Commercial Potassium Chloride) 

 Muriate of potash is a potash salt containing not les.s than forty-eight per cent 

 (48%) of potash (K2O) chiefly as chloride. 



Sulfate of Potash (Commercial Potassium Sulfate) 

 Sulfate of Potash is a potash salt containing not less than forty-eight i)er cent 

 (4S'^'c) of potash (K2O) chiefly as sulfate, and not more than two and one-half per 

 cent (2.5%) of chlorine. 



Ground Steamed Bone 

 Ground steamed bone is a product resulting from grinding animal bones that 

 have been previously steamed under pressure. 



Ground Raw Bone 

 Ground raw bone is a product resulting from drying and grinding animal bones 

 that have not been previously steamed under pressure. 



Tankage 



This term (without qualification) shall be restricted to meat and bone tankage 

 derived from the rendered, dried, and ground by-products from the slaughter of 

 animals, or from carcasses of animals that have died otherwise than by slaughter. 



Fish Tankage, Fish Scrap, Dry Ground Fish, Fish Meal Fertilizer Grade. 

 Fish tankage, fish scrap, dry ground fish, fish meal fertilizer grade, is 



the dried ground product derived from rendered or unrendered fish. 



Garbage Tankage 



Garbage tankage is the rendered, dried, and groimd product derived from 



\vaste household food materials. 



Crude, Inert, or Slow- Acting Nitrogenous Materials 

 Crude, inert, or slow-acting nitrogenous materials are unprocessed organic 

 substances relatively high in nitrogen but having a very low value as plant food 

 and showing a low activitj- by both the alkaline and neutral permanganate methods 

 (below fiftv per cent (50%) and eighty per cent (80%) respectively). 



Hoof and Horn Meal 

 Hoof and horn meal is a product resulting from tlie processing, drying, and 

 grinding of hoofs and horns. 



Superphosphate 

 Superphosphate is the product resulting froin mixing rock phosphate and 

 sulfuric acid and or phosphoric acid. The grade shoukl always be used as a prefix 

 to the name. Example: 16% Superi)hosphate. 



It is recommended that the use of the term "Acid Phosphate" be discontinued. 



VEGETATION POT EXPERIMENT TO DETERMINE NITROGEN AVAIL- 

 ABILITY OF PROCESSED LOW-GRADE MATERIALS, ACTIVATED 

 SEWAGE AND OTHER ORGANIC FERTILIZERS. 



This is a report of results of a vegetation pot experiment and is a continuation of 

 work begun five years ago in an efTort to study the actual availability of the nitro- 

 gen in processed low-grade fertilizing materials valued chiefly for their content of 

 organic^ nitrogen. For those materials under experiment for more than one year, 

 the samples employed the previous season were not used in 1929 : new samples were 

 secured which in most cases represent the products as manufactured in January or 

 Februarv of 1929. 



