Inoculation with N2-generating denitrifier strains mitigates N2O emission from agricultural soil fertilized with poultry manure

Abstract

Pelleted poultry manure is recommended for use with agricultural soil as a replacement for chemical fertilizers; however, application of the manure stimulates nitrous oxide (N2O) emission from the soil through denitrification. To mitigate the N2O emission caused by application of pelleted poultry manure, soil microcosms were set up; each microcosm was inoculated with one of the following N2-generating denitrifier strains previously been isolated from paddy soil: Azoarcus, Dyella, Dechloromonas, Niastella, and Burkholderia. When pelleted poultry manure was incubated on its own, N2O was produced by denitrification. In contrast, N2O emission was significantly lowered when the manure was inoculated with most of the N2-generating strains. In soil microcosms, N2O was emitted during incubation after application of the pelleted manure, while N2O flux was significantly lowered when the soil was inoculated with Azoarcus sp. KS11B, Niastella sp. KS31B, or Burkholderia sp. TSO47-3 on the 12th day of incubation. In addition, when pelleted manure was inoculated with the strains prior to application in the soil microcosms, the level of N2O emission was significantly lowered to ca. 40–60 % that from the non-inoculated control. Our study provides the prototype of a technique that uses microbial technology to mitigate N2O emission from agricultural soil fertilized with pelleted poultry manure.