ARS | Publication request: Microbial inoculants as tools for reducing nitrous oxide emissions from soil

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 18, 2011
Publication Date: October 18, 2011
Citation: Calvo-Valez, P., Watts, D.B., Torbert III, H.A., Kloepper, J.W. 2011. Microbial inoculants as tools for reducing nitrous oxide emissions from soil [abstract]. ASA-CSSA-SSSA International Annual Meeting, October 16-19, 2012, San Antonio, Texas. CDROM.

Technical Abstract: Over the past few decades, emissions of nitrous oxide (N2O) have increased worldwide due to several factors, including increases in cultivated crop area, use of synthetic nitrogen fertilizers, and livestock production. New management tools are needed to reduce N2O emissions from production agriculture. One potential tool for this goal is the use of microbial inoculants, which are increasingly used in agriculture. The present study compared emissions of N2O and CO2 following applications of microbial based products to soil under controlled conditions. Treatments consisted of SoilBuilder (SB), a metabolite extract of SoilBuilder (SBF), and a mixture of plant growth-promoting rhizobacteria (PGPR). Experiments included four different nitrogen fertilizers (urea, urea ammonium nitrate 32% N (UAN), calcium ammonium nitrate 17% N (CAN) and ammonium nitrate) and a no-fertilizer control. After 29 days of evaluation, all microbial treatments reduced N2O production from soils fertilized with CAN and UAN but not soils fertilized with urea or ammonium nitrate. Emissions of N2O were reduced by 80.7% with SBF in soil treated with CAN and by 42.7% with SB in soil treated with UAN. Overall, emissions of CO2 were increased by microbial treatments in soils with all four fertilizers, indicating that microbial activity was increased. Overall, the results of this study demonstrate that microbial inoculants can reduce emissions of N2O associated with nitrogen fertilizer application, but this response varies with the type of microbial inoculant and fertilizer. Future studies are needed to confirm the results under greenhouse and field conditions.