Effects of Biological Nitrification Inhibitor on Nitrous Oxide and nosZ, nirK, nirS Denitrifying Bacteria in Paddy Soils

Abstract

This study aimed to investigate the effects of a biological nitrification inhibitor on nitrous oxide emission and rice yield quality in paddy soils and its effects on denitrifying the bacteria of nosZ, nirK, and nirS types. Two treatments were performed: (1) using a local conventional fertilizer as the control CK; (2) using the partial application of a conventional fertilizer + biological nitrification inhibitor as SW. N2O emission was measured using gas chromatography; qPCR amplification was performed using primers for the targeted functional genes, nosZ, nirS, and nirK, and denitrifying functional gene abundance and denitrifying microbial community structure were analyzed using fluorescence quantification and high–throughput sequencing, respectively. The results reveal that the biological nitrification inhibitor resulted in a 41.83% reduction in N2O, relative to the normal fertilizer treatment. Meanwhile, rice yield increased by 15.45% and related quality indexes were also improved. This can promote the reproduction of bacteria with the nosZ gene while inhibiting the growth of bacteria with nirS and nirK genes. The core bacteria, Nitrosospira, Rhodanobacter, Bradyrhizobium, Tardiphaga, Rhodopseudomonas, and Paracoccus, positively correlated with N2O emissions, while core bacteria Azospirillum, Burkholderia, and Mesorhizobium negatively correlated with N2O emissions. Therefore, the application of a biological nitrification inhibitor could be an effective measure to promote rice yield and quality, reduce N2O emissions, and affect key denitrifying bacteria.

Impacts of Climate Change and Agricultural Practices on Nitrogen Processes, Genes, and Soil Nitrous Oxide Emissions: A Quantitative Review of Meta-Analyses

“…For example, Xu et al [50] reported that warmer and drier conditions have led to reduced N 2 O emissions, with soil N 2 O being closely associated with the abundance of AOB, nirK, and nosZ genes. Meanwhile, Huang et al [51] demonstrated a 41.83% reduction of soil N 2 O emission induced by a biological nitrification inhibitor, attributing the reduction to the promotion of bacteria with the nosZ gene, while the growth of bacteria with nirS and nirK genes was inhibited. While these studies have contributed valuable insights, the presence of disparities and contradictions among individual findings underscores the need for a systematic approach.…”

Examining the impact of controlled-release fertilizers on mitigating nitrous oxide emissions in pepper cultivation regions

“…) 이온 이 미생물에 의해서 산화 되고 이후 탈질작용에 의해 아산화질 소가 배출되는 것이다 [13] )이 일산화질소(NO), 아산화질소(N 2 O) 그리고 마지막 질소(N 2 )로 환원 되는 과정으로 산소가 제한된 조건에서 발생 하게 된다 [8,14]. 아질산염(NO 2  ) 환원 효소를 암호화하는 nirK 또는 NirS 등의 유전자는 아질산염을 일산화질소(NO)로 환원시 키며 N 2 O 환원 효소를 코딩하는 nosZ 유전자는 아산화질소 (N 2 O)를 질소가스(N 2 )로 환원하는데 관여한다 [6,14].…”

“…탈질화 관련 유전자 발현 분석 무처리, 요소비료, 그리고 완효성 비료를 사용한 토양 내의 탈 질화 과정에 관여하는 유전자(nirK, nirS, 그리고 nosZ)의 증폭 수준을 semi-quantitative 방법으로 분석하였다(Fig.4). nirK, nirS, nosZ는 토양 내의 탈질화에 관여하는 유전자로 보고되어 있다[6,14]. nirK와 nirS는 아질산염에서 일산화질소를 생성하는 데 관여하는 nitrite reductase를 코딩하는 유전자이고 nosZ는 일…”