40 CONTROL SERIES No. 45 



water soluble organic nitrogen .37%, water insoluble nitrogen 9.03%, total 

 phosphoric acid 7.40%. 



Cottonseed Meal. Received through trade channels Mar. 2, 1928. Anal- 

 ysis: total nitrogen 6.41%, ammoniacal nitrogen .05%, nitric nitrogen none, 

 water soluble organic nitrogen .44%, water insoluble nitrogen 5.92%, total 

 phosphoric acid 3.98%, potassium oxide 2.18%. 



Castor Pomace. Received through trade channels Mar. 2, 1928. Analysis: 

 total nitrogen 5.16%, ammoniacal and nitric nitrogen none, water soluble organic 

 nitrogen .28%, water insoluble nitrogen 4.88%, total phosphoric acid 2.55%, 

 potassium oxide 1.04%. 



Packing House Tankage (9.50 ammonia, grade). Received through trade 

 channels Mar. 2, 1928. Analysis: total nitrogen 8.39%, ammoniacal nitrogen 

 .13%, nitric nitrogen none, water soluble organic nitrogen 1.08%, water insoluble 

 organic nitrogen 7.18%, total phosphoric acid 8.62%. 



Packing House Tankage (10 ammonia, grade). Received through trade 

 channels Mar. 2, 1928. A mechanical mixture of hoof and horn meal, tankage 

 containing the stomach contents of slaughtered animals, groimd bone, stick 

 tankage or blood. Analysis: total nitrogen 7.94%, ammoniacal nitrogen .22%, 

 nitric nitrogen none, water soluble organic nitrogen 3.39%, water insoluble 

 nitrogen 4.33%, total phosphoric acid 9.34%. 



Omega Tankage. International Agricultural Corporation. Mar. 2, 1928. 

 Analysis: total nitrogen 8.40%, ammoniacal nitrogen .23%, nitric nitrogen 

 none, water soluble organic nitrogen 1.26%, water insoluble nitrogen 6.91%, 

 total phosphoric acid 1.05%. 



Super Nite. Received through trade channels Mar. 27, 1928. Analysis: 

 total nitrogen 12.04%, ammoniacal nitrogen .16%, nitric nitrogen none, water 

 soluble organic nitrogen .83%, water insoluble nitrogen 11.05%, total phos- 

 phoric acid 1.40%. 



Avail Tankage. Western Fertihzer Products Co. Received through trade 

 channels Mar. 27, 1928. Analysis: total nitrogen 7.33%, ammoniacal nitrogen 

 .43%, nitric nitrogen none, water soluble organic nitrogen 1.16%, water insoluble 

 nitrogen 5.75%, total phosphoric acid .74%. 



Nitrogenous Tankage. Fertihzer By-Products Co. Received through 

 trade channels Mar. 27, 1928. Analysis: total nitrogen 5.69%, ammoniacal 

 nitrogen .04%, nitric nitrogen none, water soluble organic nitrogen none, water 

 insoluble nitrogen 5.65%, total phosphoric acid .65%. 



Uric Acid. Purchased through Eastman Kodak Co., Rochester, N. Y., Mar. 

 27, 1928. Analysis: total nitrogen 33.02%, ammoniacal and nitric nitrogen 

 none, water soluble organic nitrogen .07%, water insoluble nitrogen 32.95%. 



The water insoluble nitrogen in some grades of Peruvian Guano has been 

 known to give comparatively low nitrogen activity by the alkahne laboratory 

 method. It is the belief of some authorities that this low nitrogen activity is 

 due to the presence of mic acid. This comparatively pure uric acid was therefore 

 included in this experiment in order to secure reliable data as to its actual nitro- 

 gen availability. 



Outline of the Experiment. 



Each pot received 38 pounds of soil mixture (one part loam from nitrogen 

 deficient soil. Plot 9, North Soil Test, West End, and three parts of sifted sand). 

 The fertihzers were mixed with the entire amoimt of soil in each pot, the amoimt 

 of each material used being as follows: 14 grams of fine ground limestone, 5 

 grams each of muriate of potash and potash-magnesium sulfate, 23/^ grams of 

 high-grade sulfate of potash, 18 grams each of 16% superphosphate (acid phos- 

 phate) and basic slag phosphate. The nitrogen containing materials were 

 applied in unit quantity sufficient to supply .42 grams of nitrogen. 



