Thiocyanate increases the nitrous oxide formation process through modifying the soil bacterial community

Area of Science:

• Environmental Science
• Soil Science
• Agricultural Science

Background:

• Nitrous oxide (N₂ O) is a potent greenhouse gas with stratospheric ozone-depleting properties.
• Previous research indicated a positive correlation between thiocyanate (TC) excretion in cattle urine and N₂ O-nitrogen (N) emissions.
• The role of TC in N₂ O-N emissions from soil requires further investigation.

Purpose of the Study:

• To investigate the effect of thiocyanate (TC) on N₂ O-N emissions from soil.
• To elucidate the mechanism by which TC influences N₂ O-N emissions using artificial urine.
• To analyze the impact of TC on soil inorganic nitrogen and bacterial communities.

Main Methods:

• Utilized a static incubation technique to measure N₂ O-N emissions.
• Applied artificial urine with four different TC concentrations (0.00, 0.26, 0.78, and 2.33 mmol L^-1).
• Analyzed soil inorganic N and bacterial community composition.

Main Results:

• Increasing TC levels significantly enhanced N₂ O-N fluxes and emissions from soil, showing both linear and quadratic relationships.
• TC addition did not alter soil bacterial diversity or richness.
• TC increased the relative abundance of Nitrosomonas and other denitrifying bacteria, suggesting a role in denitrification.

Conclusions:

• Thiocyanate (TC) enhances N₂ O-N emissions from soil treated with artificial urine.
• The mechanism likely involves the promotion of denitrification by nitrifying bacteria.
• Further field studies are recommended to validate these laboratory findings.