Nitrous oxide emissions from nitrogen-enriched cattle manure compost pellets applied to an Andosol

High levels of nitrous oxide (N 2O) are emitted when manure compost pellets are applied to soil. In order to find ways to decrease this emission, we studied the N 2O emissions for nitrogen-enriched manure compost pellets; preliminary incubation tests showed that these pellets produced lower N 2O emissions than the commonly used manure compost pellets. In the field experiments, 4 types of manure—nitrogen-enriched manure compost pellets (N + MCP), manure compost pellets (MCP), nitrogen-enriched manure compost (N + MC, non-pelletized), and manure composts (MC, non-pelletized)—were applied to a forage corn field in autumn 2008 and summer 2009, and the N 2O emissions during each treatment were measured. The total N 2O emission rates (kg N/ha) in the 2 cultivation periods were 2.519 (MCP treatment), 0.755 (N + MCP treatment), 0.441 (MC treatment), 0.287 (N + MC treatment), and 0.150 (control treatment). The emission rate during the N + MCP treatment was slightly higher than that during the non-pelletized manure treatment (MC and N + MC treatment) but significantly lower than that during the MCP treatment. These results indicate that the use of nitrogen-enriched manure compost pellets resulted in a decrease in the N 2O emissions from manure compost pellets applied to the soil.