Nitrogen losses in urine
1919
Bear, F.E. | Royston, J.R.
An inquiry into the losses of nitrogen from the urine of farm animals was thought desirable because many farmers practice storing the liquid manure in tanks until convenient to apply it to the land. The question of the efficiency of these tanks in preserving the urine has often arisen. In these investigations a study was made as to nitrogen losses from urine (a) exposed to the open air, (b) in Bunsen valve flasks, (c) in closed flasks, (d) in closed flasks with the air displaced with carbon dioxide, (e) absorbed in litter, and (f) protected by layers of kerosene. It was observed that urine exposed to the air lost over 92 percent of its nitrogen over a period of 8 weeks under temperatures averaging 38 degrees C. Under temperatures averaging 5 degrees less, approximately the same losses occurred over a period of 12 weeks. For shorter periods of time the losses were somewhat smaller at the lower temperatures. With urine not exposed to the air practically no losses took place under the various conditions of temperature, time, and methods of control. The effectiveness in preventing nitrogen losses by absorption of the urine in litter (filter paper) depended upon the method of handling the litter. Litter which was allowed to dry out and remain lost approximately 20 percent of its nitrogen content. On the other hand, litter kept in a moist condition by the daily addition of water lost over 97 perc ent of its nitrogen, the greatest loss which occurred in any of the samples. Kerosene provided a fairly satisfactorily means of preventing nitrogen losses. The samples of urine so protected lost approximately 6 percent of their nitrogen content over a period of 8 weeks.
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