Microbial community structure from southern High Plains beef cattle feedyard manure and relationship with nitrous oxide emissions. Issue 3 (12th August 2022)

• Record Type: Journal Article
• Authors: Waldrip, Heidi; Parker, David; Miller, Sierra; Durso, Lisa M.; Min, Byeng R.; Miller, Daniel N.; Casey, Kenneth; Woodbury, Bryan; Spiehs, Mindy J.
• Is Part Of: Agrosystems, geosciences & environment. Volume 5:Issue 3(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-12
• Subjects: Agriculture -- Periodicals; Agriculture -- Environmental aspects -- Periodicals; Soil science -- Periodicals; Food science -- Periodicals; Food science; Agriculture; Agriculture -- Environmental aspects; Electronic journals; Periodicals; 630
• DOI: 10.1002/agg2.20292
• Languages: English
• ISSNs: 2639-6696

Abstract

Abstract: Modern molecular techniques enable characterization of the microbial biome in livestock manure, from which there is particular concern over emission of greenhouse gases. This study evaluated how sampling depth, time, temperature, and artificial rainfall affected microbial community structure in feedyard manure, and relationships between the manure biome and known parameters related to nitrous oxide (N2 O) emissions. In three large incubation chambers, maintained at different temperatures that received two applications of artificial rainfall, we evaluated manure microbiome composition and abundance of N2 O‐producing enzymes ( nirK and nirS ) using quantitative polymerase chain reaction (qPCR). These data were used with previously published data from the same study on N2 O emissions and assessment of manure physicochemical properties, denitrification enzyme activity (DEA), and nitrification activity (NA). Microbiome composition was Firmicutes (50%), followed by 32% Actinobacteria, 11% Proteobacteria, 5% Bacteroidetes, 1% Chloroflexi, and small populations (<0.5%) of Planctomycetes, Deinococcus‐Thermus, Gemmatimonadetes, Verrucomicrobia, Tenericutes, and other organisms. Average bacterial populations varied largely as a function of sampling depth and time. Firmicutes increases tended to coincide with high N2 O emissions. Overall, the largest change observed was increased Proteobacteria at 5–10 cm, where relative abundance increased from 10% (17.2 °C) to 24% (46.2 °C) over time and with increased temperature. Firmicutes and Actinobacteri a predominated the microbial community of manure, but favorable conditions may lead to increases in Bacteroidetes, Proteobacteria, and Chloroflexi, which could influence N cycling and N2 O emissions from feedyards. Copy numbers of nirS at the beginning of the experiment were higher than nirK . Differences in concentrations of nirK and nirS indicated that denitrifying enzymes in feedyard manure, particularly nirS, were sensitive to environmental changes. Core Ideas: Relationships were established among the beef manure microbiome, nitrous oxide losses, and environmental conditions. The predominant manure microbiome was Firmicutes > Actinobacteria > Proteobacteria > Bacteroidetes > Chloroflexi > others. Average microbial populations varied with sampling depth and time. Increases in Firmicutes coincided with nitrous oxide emissions. Copy numbers of nirK and nirS differed with date and among chambers, indicating sensitivity of denitrifying enzymes to environmental changes.