干旱区生态环境知识资源中心(Arid): Mechanisms behind high N 2 O emissions from livestock enclosures in Kenya revealed by dual-isotope and functional gene analyses

Arid

DOI	10.1016/j.soilbio.2024.109505
	Mechanisms behind high N 2 O emissions from livestock enclosures in Kenya revealed by dual-isotope and functional gene analyses
	Fang, Xiantao; Harris, Stephen J.; Leitner, Sonja Maria; Butterbach-Bahl, Klaus; Conz, Rafaela Feola; Merbold, Lutz; Dannenmann, Michael; Oyugi, Antony; Liu, Shuwei; Zou, Jianwen; Six, Johan; Barthel, Matti
通讯作者	Fang, XT
来源期刊	SOIL BIOLOGY & BIOCHEMISTRY
ISSN	0038-0717
EISSN	1879-3428
出版年	2024
卷号	196
英文摘要	Livestock manure contributes to global warming due to greenhouse gas (GHG) emissions, especially nitrous oxide (N 2 O) and methane (CH 4 ). In the arid and semi-arid lands of Sub-Saharan Africa (SSA), extensive pastoral grazing systems are common, with cattle grazing in the savanna during the day and kept in enclosures (called bomas in Kenya) during the night. Manure is usually not removed from bomas but left to accumulate, leading to excessive local nitrogen loads, making these bomas an overlooked N 2 O emission hotspot in SSA that is currently not accounted for in national and regional GHG budgets. Here, we present the first in-situ isotope measurements of N 2 O fluxes from 37 cattle bomas along an age gradient ranging from 0 to 5 years after boma abandonment in Kenya along with functional gene analysis of soil and manure samples. The isotopic composition of the emitted N 2 O from bomas suggests that on average 91 +/- 8% N 2 O was produced via bacterial denitrification and/or nitrifier denitrification, with little variation across boma age class. We also found high levels of N 2 O reduction to N 2 across all sample sites (81 +/- 9%), indicating high levels of N 2 O consumption. The abundances of denitrification-related genes (nirK and narG ) were significantly higher than those of nitrification-related genes ( amoA : AOA and AOB) in the cattle manure samples taken from the bomas, corroborating N 2 O emissions largely being attributed to denitrification. Significant abundance of the reduction-related gene ( nosZ ) also corroborated the high potential for microbial N 2 O reduction in bomas. Thus, by combining dual-isotope and functional gene analysis, we were able to identify source processes that govern N 2 O emissions from these systems. More generally, making use of the manure by spreading it in the vicinity of the bomas or on dedicated forage plots could provide a win-win by enhancing savanna productivity while simultaneously mitigating GHG emissions.
英文关键词	N2O Boma Dual isotope mapping approach Site preference Functional genes
类型	Article
语种	英语
开放获取类型	hybrid
收录类别	SCI-E
WOS记录号	WOS:001266479700001
WOS关键词	NITROUS-OXIDE EMISSIONS ; ABANDONED PASTORAL SETTLEMENTS ; GREENHOUSE-GAS EMISSIONS ; NITRIFIER DENITRIFICATION ; N2O EMISSIONS ; NOSZ GENES ; N-15 ; SOIL ; ECOSYSTEMS ; REDUCTION
WOS类目	Soil Science
WOS研究方向	Agriculture
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/405660
推荐引用方式 GB/T 7714	Fang, Xiantao,Harris, Stephen J.,Leitner, Sonja Maria,et al. Mechanisms behind high N 2 O emissions from livestock enclosures in Kenya revealed by dual-isotope and functional gene analyses[J],2024,196.
APA	Fang, Xiantao.,Harris, Stephen J..,Leitner, Sonja Maria.,Butterbach-Bahl, Klaus.,Conz, Rafaela Feola.,...&Barthel, Matti.(2024).Mechanisms behind high N 2 O emissions from livestock enclosures in Kenya revealed by dual-isotope and functional gene analyses.SOIL BIOLOGY & BIOCHEMISTRY,196.
MLA	Fang, Xiantao,et al."Mechanisms behind high N 2 O emissions from livestock enclosures in Kenya revealed by dual-isotope and functional gene analyses".SOIL BIOLOGY & BIOCHEMISTRY 196(2024).