Land Use Modulates Viral Impacts on Soil Nitrification and Denitrification

Area of Science:

• Soil microbiology
• Environmental science
• Biogeochemistry

Background:

• Land use and soil viruses are key drivers of microbial communities and nitrogen cycling.
• The interplay between land use and viral impacts on soil microbial dynamics, nitrification, and denitrification is not well understood.

Purpose of the Study:

• To investigate how land use influences the effects of soil viruses on microbial communities, nitrification, and denitrification.
• To elucidate the mechanisms behind viral modulation of nitrogen cycling under different land-use scenarios.

Main Methods:

• Microcosm experiments using sterilized forest, greenbelt, and agricultural soils.
• Inoculation with microbial suspensions and either active or inactivated viral suspensions.
• Analysis of bacterial and fungal community composition, potential nitrification and denitrification rates, and N2O emissions over 14 and 56 days.

Main Results:

• Active virus addition increased bacterial abundance and altered microbial community structure across all land uses.
• Viral addition differentially affected potential nitrification rates (decreased in forest/agricultural, increased in greenbelt soils).
• Potential denitrification and N2O emission rates varied by land use, with active viruses altering N2O production pathways in forest and agricultural soils.

Conclusions:

• Active soil viruses play a significant role in shaping soil microbial communities and nitrogen cycling, with effects modulated by land use.
• Viral impacts on nitrogen cycling are associated with land-use-specific soil nutrients, microbial communities, and virus-like particles (VLPs).
• Soil type and incubation time are critical factors influencing the response of nitrogen-cycling indicators to viral addition in microcosm settings.