Long-term effects of nitrogen and phosphorus fertilization on soil microbial community structure and function under continuous wheat production.
Li, Y., J. Tremblay, L. D. Bainard, B. Cade-Menun and C. Hamel. 2020.
Abstract
Soil microorganisms play a critical role in the biosphere, and the influence of cropland
fertilization on the evolution of soil as a living entity is being actively documented. In this study,
we used a shotgun metagenomics approach to globally expose the effects of 50-year N and P
fertilization of wheat on soil microbial community structure and function, and their potential
involvement in overall N cycling. Nitrogen (N) fertilization increased alpha diversity in archaea
and fungi while reducing it in bacteria. Beta diversity of archaea, bacteria, and fungi, as well as
soil function, were also mainly driven by N fertilization. The abundance of archaea was
negatively impacted by N fertilization while bacterial and fungal abundance was increased. The
responses of N-metabolism-related genes to fertilization differed in archaea, bacteria, and fungi.
All archaeal N metabolic processes were decreased by N fertilization, while denitrification,
assimilatory nitrate reduction and organic-N metabolism were highly increased by N fertilization
in bacteria. Nitrate assimilation was the main contribution of fungi to N cycling.
Thaumarchaeota and Halobacteria in archaea; Actinobacteria, alpha-, beta-, gamma-, and delta
Proteobacteria in bacteria; and Sordariomycetes in fungi participated dominantly and widely in
soil N metabolic processes.
