Organic fertilization reduces nitrous oxide emission by altering nitrogen cycling microbial guilds favouring complete denitrification at soil aggregate scale

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 946, P. 174178 - 174178

Published: June 24, 2024

Agricultural management practices can induce changes in soil aggregation structure that alter the microbial nitrous oxide (N2O) production and reduction processes occurring at microscale, leading to large-scale consequences for N2O emissions. However, mechanistic understanding of how organic fertilization affects these context-dependent small-scale emissions associated key nitrogen (N) cycling communities is lacking. Here, denitrification gas (N2O, N2) potential capacity N2O/(N2O + were assessed by automated chromatography different aggregates (>2 mm, 2–0.25 <0.25 mm), while sequencing qPCR N2O-producting (nirK nirS) reducing (nosZ clade I II) genes. The results indicated reduced enhancing conversion N2 all aggregate sizes. Moreover, hotspots occurred smaller aggregates, with degree depending on fertilizer type application rate. Further, significantly higher abundance diversity nosZ clades relative nirK nirS revealed complete promoted through selection denitrifying microscales favouring reduction. Communities high low emission treatments form modules specific sequence types which may be diagnostic levels. Taken together, findings suggest fertilizers influencing factors patterns niche partitioning between N2O-producing within overall are more likely consume than emit N2O. These helpful strengthening ability predict from agricultural soils under as well contributing development net-zero carbon strategies sustainable agriculture.

Language: Английский

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Anthropogenic N input increases global warming potential by awakening the “sleeping” ancient C in deep critical zones

Science Advances, Journal Year: 2023, Volume and Issue: 9(6)

Published: Feb. 8, 2023

Even a small net increase in soil organic carbon (SOC) mineralization will cause substantial the atmospheric CO2 concentration. It is widely recognized that SOC within deep critical zones (2 to 12 m depth) slower and much less influenced by anthropogenic disturbance when compared of surface soil. Here, we showed 20 years nitrogen (N) fertilization enriched zone with nitrate, almost doubling rate. This result was supported corresponding increases expressions functional genes typical recalcitrant degradation enzyme activities. The released had similar 14C age (6000 10,000 before present). Our results indicate N crops may enhance emissions from atmosphere through previously disregarded mechanism. provides another reason for markedly improving management fertilized agricultural soils.

Language: Английский

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Plant species diversity enhances soil gross nitrogen transformations in a subtropical forest, southwest China

Journal of Applied Ecology, Journal Year: 2023, Volume and Issue: 60(7), P. 1364 - 1375

Published: March 30, 2023

Abstract Plant species diversity (PSD) regulates ecosystem structure and functions, is a key issue we need to consider when design vegetation restoration projects. Increasing PSD has been shown promote or decrease soil nitrogen (N) availability, but the underlying mechanisms have not well explored. Here, 45 plots with Shannon–Weiner indices ranging from 0.15 3.57 were selected in subtropical forest explore effect of on N transformations. Higher significantly enhanced rates gross mineralization, nitrification, microbial immobilization, net nitrification contents total inorganic N. Structural equation modelling showed that indirectly impacted transformations via its roles regulating organic matter, mineral traits. stimulated mineralization mainly positive effects biomass content gene abundances chiA , archaeal bacterial amoA while increased immobilization due stimulation matter. Synthesis applications . Our findings highlight crucial role stimulating availability provide mechanistic understanding which can be integrated into Earth system models better predict C sequestration response PSD.

Language: Английский

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A large nitrogen supply from the stable mineral-associated soil organic matter fraction

Biology and Fertility of Soils, Journal Year: 2023, Volume and Issue: 59(7), P. 833 - 841

Published: July 11, 2023

Language: Английский

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Expression of macromolecular organic nitrogen degrading enzymes identifies potential mediators of soil organic N availability to an annual grass

The ISME Journal, Journal Year: 2023, Volume and Issue: 17(7), P. 967 - 975

Published: April 14, 2023

Abstract Nitrogen (N) is frequently limiting to plant growth, in part because most soil N present as polymeric organic compounds that are not readily taken up by plants. Microbial depolymerization of these large macromolecular N-substrates gradually releases available inorganic N. While many studies have researched and modeled controls on matter formation bulk mineralization, the ecological—spatial, temporal phylogenetic—patterns underlying degradation remain unclear. We analyzed 48 time-resolved metatranscriptomes quantified N-depolymerization gene expression resolve differential habitat time specific taxonomic groups gene-based guilds. observed much higher extracellular serine-type proteases than other N-degrading enzymes, with protease predatory bacteria declining patterns driven presence (Gammaproteobacteria) or absence (Thermoproteota) live roots root detritus (Deltaproteobacteria Fungi). The primary chitinase chit1 was more highly expressed eukaryotes near detritus, suggesting predation fungi. In some lineages, increased over suggests competitiveness rhizosphere age (Chloroflexi). Phylotypes from genera had could benefit nutrition, for example, we identified a Janthinobacterium phylotype two Burkholderiales depolymerize young Rhizobacter elevated levels mature roots. These taxon-resolved results provide an ecological read-out microbial interactions dynamics microhabitats be used target potential bioaugmentation strategies.

Language: Английский

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