Reduction of Ammonia Emission during Composting of Poultry Manure by Covering with Cedar Bark

The aim was to investigate the extent of reduction of ammonia emissions from poultry manure by utilizing cedar bark, which occurs plentifully from timber trimming facilities and has an ability to adsorb ammonia. In a laboratory scale study, cedar bark meal was contacted with an ammonia concentration of 620 ppm in Tedlar bags for 5 minutes. The result showed that the bark reduced ammonia by 99.5%. This study compiled data on ammonia above poultry manure covered with cedar saw dust or cedar bark during a period of 3 weeks. The results indicated that both types of covering agents achieved significant reductions in ammonia concentrations. The adsorption of ammonia was 11 mg.g(-1) and 33 mg.g(-1) for saw dust and bark respectively. Water-soluble nitrogen, ionic nitrogen, and organic nitrogen accounted for 22%, 23% and 47%, respectively, of increased nitrogen in the bark during composting. It suggested that the increase in ionic nitrogen was due to the higher cation exchange capacity. The increase in organic nitrogen may be attributed to covalent bonds. The results showed that the reduction in the emission of ammonia appears to be caused by the bark cover acting as an inexpensive and simple deodorizer.