Eff ects of Reed Straw, Zeolite, and Superphosphate Amendments on Ammonia and Greenhouse Gas Emissions from Stored Duck Manure

Stored poultry manure can be a significant source of ammonia (NH3) and greenhouse gases (GHGs), including nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) emissions. Amendments can be used to modify physiochemical properties of manure, thus having the potential to reduce gas emissions. Here, we lab-tested the single and combined effects of addition of reed straw, zeolite, and superphosphate on gas emissions from stored duck manure. We showed that, over a period of 46 d, cumulative NH3 emissions were reduced by 61 to 70% with superphosphate additions, whereas cumulative N2O emissions were increased by up to 23% compared with the control treatment. Reed straw addition reduced cumulative NH3, N2O, and CH 4 emissions relative to the control by 12, 27, and 47%, respectively, and zeolite addition reduced cumulative NH3 and N2O emissions by 36 and 20%, respectively. Total GHG emissions (as CO2-equivalents) were reduced by up to 27% with the additions of reed straw and/or zeolite. Our results indicate that reed straw or zeolite can be recommended as amendments to reduce GHG emissions from duck manure; however, superphosphate is more effective in reducing NH3 emissions.