[Nitric oxide production in rice soils (author's transl)]

Area of Science:

• Soil Science
• Environmental Chemistry
• Microbiology

Context:

• Nitric oxide (NO) is a key gas in nitrogen cycling.
• Understanding NO evolution from nitrite in soils is crucial for environmental and agricultural applications.
• Previous studies have focused on abiotic factors, but the biological contribution requires further elucidation.

Purpose:

• To investigate the in vitro evolution of nitric oxide (NO) gas from nitrite in three distinct rice soil types.
• To differentiate between abiotic and biological contributions to NO formation under varying environmental conditions.
• To identify soil characteristics and microbial populations influencing NO production.

Summary:

• Nitric oxide (NO) evolution from nitrite was studied in three rice soils using gas chromatography.
• While autoclaved soils showed NO production, one soil exhibited a partially biological NO production process.
• NO formation was higher in non-sterile soil, decreased with increasing temperature, and was optimal near neutral pH and with increased soil moisture.
• This soil also showed less increase in NO formation with increasing nitrite concentration and harbored more high-nitrite-tolerant denitrifying bacteria.

Impact:

• This research highlights the significant role of microbial denitrification in nitric oxide (NO) emissions from soils.
• Findings provide insights into factors controlling NO production in agricultural ecosystems, impacting greenhouse gas inventories and soil health.
• Identifies specific soil microbial communities and conditions that influence nitrogen gas fluxes.