36 



VEGETATION POT EXPERIMENT TO DETERMINE NITROGEN 



AVAILABILITY. 



There are from time to time new processed organic ammoniates coming into the 

 fertilizer market which naturally gravitate into the complete mixed fertilizers. 

 As most of these products were originally low-grade organic materials unfit for 

 use in high-grade mixed fertihzers until properly processed, it seems desirable 

 that vegetation tests should be made in order to show the comparative nitrogen 

 availabiUty of the finished products. Tests were made during the past season 

 on two products examined in 1925, Rehmsdorf Tankage and Pulverized Poultry 

 Manure, the experiment being extended to include four other materials, namely, 

 Ammoniate A, Ammoniate B, HjTiite Tankage, and a mixture of Horn and Hoof 

 Meal. 



Description of the Products. 



The Rehmsdorf Tankage and Pulverized Poultry Manure were described in 

 Control Bulletin 33, 1925, page 13. 



Ammoniate A and Ammoniate B are manufactured by the Fertilizer By-Products 

 Co., Norfolk, Va. These materials are said to be specially processed leather prod- 

 ucts without the use of acid and without carbonization. Ammoniate B is the 

 very fine product separated by air blasts and collected in dust chambers. 



Hynite Tankage is made by the United FertiUzer Co., Milwaukee, Wis. It 

 is said to be a nitrogenous tanJcage made from hide clippings, wool, fur, glue hair, 

 hoofs and unground tankage, by a special digestion process, the product being 

 finally dried and ground. 



Horn and Hoof Meal is a product resulting from processing horns and hoofs, 

 and finely ground. Formerly, hoof meal was quoted unmixed with horn; more 

 recently the horn and hoof meal is quoted as a mixture of the two products, as 

 they are similar in composition and in their nitrogen activity. 



Plan of Experiment. 



The vegetation experiment conducted on these products was similar to the 

 general methods described on page 11, Control Bulletin 25, varied in detail to 

 suit the needs of this investigation. The soil used was from the same source and 

 had the same admixture of sand as was there described. It was planned to use 

 Japanese millet as the crop to be grown. The seed proved to be Japanese barn- 

 yard millet, and produced plants not so well suited for the experiment as the 

 regular Japanese millet. The appearance of the young plants did not permit of 

 the discovery of the mistake until the formation of the heads, when it was too late 

 to plant new seed. The tabulated results include both yields of dry matter and 

 nitrogen recovered in the above-ground parts of the plant. 



