title: Organic nitrogen rearranges both structure and activity of the soil-borne microbial seedbank.
abstract: Use of organic amendments is a valuable strategy for crop production. However, it remains unclear how organic amendments shape both soil microbial community structure and activity, and how these changes impact nutrient mineralization rates. We evaluated the effect of various organic amendments, which range in Carbon/Nitrogen (C/N) ratio and degradability, on the soil microbiome in a mesocosm study at 32, 69 and 132 days. Soil samples were collected to determine community structure (assessed by 16S and 18S rRNA gene sequences), microbial biomass (fungi and bacteria), microbial activity (leucine incorporation and active hyphal length), and carbon and nitrogen mineralization rates. We considered the microbial soil DNA as the microbial seedbank. High C/N ratio favored fungal presence, while low C/N favored dominance of bacterial populations. Our results suggest that organic amendments shape the soil microbial community structure through a feedback mechanism by which microbial activity responds to changing organic inputs and rearranges composition of the microbial seedbank. We hypothesize that the microbial seedbank composition responds to changing organic inputs according to the resistance and resilience of individual species, while changes in microbial activity may result in increases or decreases in availability of various soil nutrients that affect plant nutrient uptake.
authors.affiliation: Netherlands Institute of Ecology (NIOO/KNAW), Department of Microbial Ecology, Wageningen, The Netherlands.|Agroecology Program of Maranhão State University - UEMA, São Luís - MA, Brazil.
authors.forename: Márcio F A
authors.initials: MF
authors.lastname: Leite
authors.affiliation: Netherlands Institute of Ecology (NIOO/KNAW), Department of Microbial Ecology, Wageningen, The Netherlands.
authors.forename: Yao
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Alterra, Wageningen UR, The Netherlands.
authors.forename: Jaap
authors.initials: J
authors.lastname: Bloem
authors.affiliation: Plant Research International, Wageningen UR, The Netherlands.
authors.forename: Hein Ten
authors.initials: HT
authors.lastname: Berge
authors.affiliation: Netherlands Institute of Ecology (NIOO/KNAW), Department of Microbial Ecology, Wageningen, The Netherlands.
authors.forename: Eiko E
authors.initials: EE
authors.lastname: Kuramae
mesh_terms: D001419:Bacteria; D002244:Carbon / Q000737:chemistry / Q000378:metabolism; D005658:Fungi; D054892:Metagenome; D056186:Metagenomics / Q000379:methods; D064307:Microbiota; D009584:Nitrogen / Q000737:chemistry* / Q000378:metabolism*; D012988:Soil Microbiology
chemical_list: D002244:Carbon; D009584:Nitrogen