Diazotrophic Community Variation Underlies Differences in Nitrogen Fixation Potential in Paddy Soils Across a Climatic G
- PDF / 1,355,508 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 73 Downloads / 177 Views
SOIL MICROBIOLOGY
Diazotrophic Community Variation Underlies Differences in Nitrogen Fixation Potential in Paddy Soils Across a Climatic Gradient in China Chuanfa Wu 1 & Xiaomeng Wei 1,2 & Ziye Hu 3 & Yi Liu 1,4 Tida Ge 1 & Mostafa Zhran 1,5 & Yirong Su 1
1
& Yajun Hu & Hongling Qin
1,4
1
& Xiangbi Chen & Jinshui Wu
1,2
&
Received: 16 April 2020 / Accepted: 28 August 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract Biological nitrogen (N2) fixation as a source of new N input into the soil by free-living diazotrophs is important for achieving sustainable rice agriculture. However, the dominant environmental drivers or factors influencing N2 fixation and the functional significance of the diazotroph community structure in paddy soil across a climatic gradient are not yet well understood. Thus, we characterized the diazotroph community and identified the ecological predictors of N2 fixation potential in four different climate zones (mid-temperate, warm-temperate, subtropical, and tropical paddy soils) in eastern China. Comprehensive nifH gene sequencing, functional activity detection, and correlation analysis with environmental factors were estimated. The potential nitrogenase activity (PNA) was highest in warm-temperate regions, where it was 6.2-, 2.9-, and 2.2-fold greater than in the tropical, subtropical, and midtemperate regions, respectively; nifH gene abundance was significantly higher in warm-temperate and subtropical zones than in the tropical or mid-temperate zones. Diazotroph diversity was significantly higher in the tropical climate zone and significantly lower in the mid-temperate zone. Non-metric multidimensional scaling and canonical correlation analysis indicated that paddy soil diazotroph populations differed significantly among the four climate zones, mainly owing to differences in climate and soil pH. Structural equation models and automatic linear models revealed that climate and nutrients indirectly affected PNA by affecting soil pH and diazotroph community, respectively, while diazotroph community, C/P, and nifH gene abundance directly affected PNA. And C/P ratio, pH, and the diazotroph community structure were the main predictors of PNA in paddy soils. Collectively, the differences in diazotroph community structure have ecological significance, with important implications for the prediction of soil N2-fixing functions under climate change scenarios. Keywords Climate zone . Paddy soil . Rice . Nitrogen fixation . Potential nitrogenase activity . Diazotrophs
Introduction Rice (Oryza sativa L.) is the major source of daily calorie intake for half of the global population [1]. Its production is
mainly limited by nitrogen (N) fertilizer, and owing to the ever-growing demand for rice, nitrogen fertilizer has been intensively used to improve the productivity. However, less than 50% of applied N is absorbed by plants during the
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00248-020-01591-w) contains suppleme
Data Loading...
