Effect of anaerobic digestion on odor and ammonia emission from land-applied cattle manure.

High ammonia (NH) and odor emission can occur after land application of liquid animal manure. This study was aimed at evaluating NH loss and odor nuisance after field application of cattle manure and how it is affected by two anaerobic digestion strategies: i) digestion of cattle manure alone and ii) digestion with catch crops and dilution by water. A system of dynamic chambers with online measurements of NH and odorous compounds (summarized as odor activity value, OAV) was used. Two experiments were conducted under different temperature conditions. The results demonstrated that anaerobic digestion did not affect NH loss but did decrease OAV. Addition of catch crops and water to the digestion process reduced both NH loss and OAV. Cool temperature in one of the experiments had a large effect on both NH and odor emissions, and at high temperature the differences between treatments increased.