Long-Term Inorganic and Organic Fertilizations Affect CH4 Oxidation Potential and Methanotrophic Community Structure in Paddy Soils

Abstract

Long-term fertilizations of inorganic and organic fertilizers can affect microbial abundance and community structure in agricultural soils, particularly controlling the activities of methane (CH 4 ) microbes such as methanotrophs in the rice paddy soils. However, the effect of fertilizations on CH 4 oxidation potential and methanotrophic community remains unclear. In order to investigate the response of the soil bacterial community abundance, composition, and CH 4 oxidation potential under four different fertilization regimes (control, NPK, compost, and NPK + compost) in a 49-year old paddy field, the soil bacterial community abundance and structure including CH 4 -oxidizing microbes as well as the potential of CH 4 oxidation were investigated by assessing real time quantitative PCR (qPCR), Miseq illumina sequencing analysis based on 16S rRNA genes, and oxic in vitro slurry incubation, respectively. Long-term fertilizations changed significantly soil biochemical characteristics, mainly influencing carbon and nitrogen pools in rice paddy soils. CH 4 oxidation potential was stimulated by inorganic fertilizations, mainly increasing the relative abundance of the genus Methylosarcina probably due to increased N availability and soil pH in the soils. Our results showed inorganic fertilizations may enhance CH 4 oxidation potential by altering methanotrophic communities, which potentially mitigate CH 4 emissions in paddy ecosystems during the cultivation. However, additional research would be necessary for a better understanding of CH 4 dynamics in rice paddy soils under the long-term field conditions.

Methane emission from soil surface during rice growth season under different temperature, fertilization, and rice straw input conditions

“…한편, 토양직접방출 메탄 플럭스가 중간낙수 후 볏짚 투입구 중 상승온도 조건에서 유기질 비 료 + 퇴비가 처리된 조건에서 음의 값을 보였는데 (Fig.3), 이는 혐기적 메탄 산화일 가능성으로 판단된다. 토양의 메 탄 산화균이 메탄을 산화하는 과정에서 발생하는 전자가 전자수용체로 전달되어 전자수용체가 환원되는데(Fan et al, 2022;Yoon et al, 2022), 다른 처리구와 달리 전자수용체 (e.g., Fe 3+ , Mn 4+ )를 함유한 유기질 비료 + 퇴비 처리구 에서 이와 같은 혐기적 메탄 산화가 일어났을 것으로 추측된다(Lim and Choi, 2014;Fan et al, 2021). Kong et al (2019)의 연구 결과에 의하면, 화학비료 처리구에 비해 돈분 처리구에서 혐기적 메탄 산화에 의해 메탄 발생량이 오히 려 감소하였다.…”

The Importance of Researches on Climate-Smart Agriculture for 5C Dimension of Global Soil Security: An Overview of GSS2023

“…Numerous studies addressed the mutual relationship between soil security and climate changes with special emphasis on sustainable food production under climate change and soil management for climate change mitigation including soil carbon sequestration. In this context, soil organic matter management for sustainable rice (Oryza sativa L.) production in waterlogged paddy systems was questioned because incorporation of organic inputs to improve soil quality should increase methane (CH 4 ) emission (Yoon et al, 2022;Baek et al, 2023;Lee et al, 2023). Therefore, a strategy to produce high-quality rice in paddy while mitigating CH 4 emission needs to be developed, and this effort should make a progress on "connectivity" and "codification" dimension of soil security.…”