Divergent responses of carbon and nitrogen functional genes composition to enhanced rock weathering

Abstract

Abstract Enhanced rock weathering (ERW) is a scalable strategy for atmospheric carbon dioxide removal. The microbiome function critically regulates the below-ground cycle of carbon and nitrogen in terrestrial ecosystems. However, microbial functioning related to carbon and nitrogen under ERW remains elusive. Here we investigated how wollastonite addition affects key microbial carbon and nitrogen-cycles genes investigated using metagenomic, in a tropic rubber plantation. After two-year, ERW had enhanced the alpha diversity of biogeochemical cycling genes was mainly driven by increased soil pH. ERW led to an increase in the relative abundance of carbon-fixation genes, and a decrease in the carbon-degradation genes, providing microbiological evidence for carbon dioxide emissions. Additionally, the relative abundance of nitrogen-cycling functional genes, and available iron increased after wollastonite addition, indicating ERW may influence nitrous oxide emissions through biological and chemical processes. Altogether, our results illustrate how the effect of ERW alters microbial functioning, impacting soil organic matter dynamics.