The capacity of controlling odor emissions of low cost organic and inorganic materials used to cover manure surface was studied in a research project. 14 steel tanks of 1.83 m diameter by 1.22 m high were buried 0.9m in the soil and the tanks were filled with manure on 0.9 m (0.32 m left on top for cover treatment). Different covering materials were applied on the manure surface: chopped straw, cornstalks, polyethylene open mesh with a liquid surface film, Leka rock, and foam generated from air bubbles and manure solids. Their odor control capacity was verified by olfactometry analysis and chemical analysis of air samples taken in the headspace of each tanks weekly for 9 weeks. The chemical analysis were done with sample detector tubes on the following identified compounds: ammonia, hydrogen sulfide, ethyl mercaptan and methyl mercaptan. Results show that straw, cornstalks, Leka rock, and surface foam can reduce odors, the reusable Leka rock being the more costly ($150 to $180 U.S. /m3). For scale applications the odor reduction rate and the cost still have to be determined to find acceptable manure covering strategies. The effect of wind on the material applied on large tanks and also the covers’ longevity and integrity still have to be investigated on real scale tanks.

The behavior of those covers was not verified for large tanks; the covers giving the more promising results should be verified for field situations. Odor reduction capacities should be determined and also the techniques for cover application and maintenance. The choice of a covering strategy for farm application could than be done.