Long-term effects of nitrogen and phosphorus fertilization on soil microbial community structure and function under continuous wheat production
Citation
Li, Y., Tremblay, J., Bainard, L.D., Cade-Menun, B., Hamel, C. (2020). Long-term effects of nitrogen and phosphorus fertilization on soil microbial community structure and function under continuous wheat production. Environmental Microbiology, [online] 22(3), 1066-1088. http://dx.doi.org/10.1111/1462-2920.14824
Plain language summary
The use of synthetic fertilizers in agricultural systems can significantly alter key soil properties including organic matter, chemistry, and the microbiome. Soil microorganisms that make up the microbiome play critical roles in soil nutrient cycling that directly impact crop productivity. In this study, we used a long term experimental field trial (50+ years) to improve our understanding of the influence of nitrogen and phosphorus fertilizer use on the biodiversity and nutrient cycling capacity of the soil microbiome. We found that nitrogen fertilization was the main driver of soil microbial diversity, community structure, and function in the experimental trial. In particular, fertilization altered nitrogen cycling processes and the relative contributions of microbes responsible for these processes.
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, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Deltaproteobacteria in bacteria; and Sordariomycetes in fungi participated dominantly and widely in soil N metabolic processes.