Low nitrogen fertilization adapts rice root microbiome to low nutrient environment by changing biogeochemical...

Area of Science:

• Microbial Ecology
• Sustainable Agriculture
• Soil Science

Background:

• Reducing nitrogen (N) fertilizer is crucial for sustainable agriculture.
• Paddy rice ecosystems are sensitive to N fertilizer levels.
• Microbial communities play a vital role in soil health and plant growth.

Purpose of the Study:

• To investigate the impact of varying nitrogen fertilizer levels on bacterial communities in paddy rice root systems.
• To understand how low-N fertilizer management affects microbial structure and function.

Main Methods:

• Analysis of bacterial communities using 16S rRNA gene sequencing and metagenomics.
• Quantification of functional genes (pmoA/mcrA) using quantitative PCR.
• Stable isotope probing with (13)C methane to assess methane oxidation activity.

Main Results:

• Low N (LN) fertilizer application significantly shifted bacterial communities compared to standard (SN) and high N (HN) levels.
• Increased abundance of plant-associated bacteria (Burkholderia, Bradyrhizobium, Methylosinus) and methane-oxidizing bacteria in the LN field.
• Reduced methanogenic archaea and enhanced methane oxidation activity in the LN root microbiome.
• Upregulation of functional genes involved in methane oxidation, plant association, and metabolism of N, S, Fe, and aromatic compounds.

Conclusions:

• Low-N fertilizer management effectively reshapes the rice root microbiome.
• This management strategy promotes beneficial microbes for plant association and enhances key biogeochemical processes like methane oxidation.
• Findings support low-N fertilizer application as a sustainable practice for paddy rice ecosystems.