The influence of season, agricultural management, and soil properties on gross nitrogen transformations and bacterial community structure

Soil Research ◽  
2006 ◽  
Vol 44 (4) ◽  
pp. 453 ◽  
Author(s):  
W. R. Cookson ◽  
P. Marschner ◽  
I. M. Clark ◽  
N. Milton ◽  
M. N. Smirk ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Soil Temperature ◽  
Bacterial Community Structure ◽  
Dominant Factor ◽  
Organic N ◽  
N Fluxes ◽  
C And N ◽  
C And N Pools ◽  
Semi Arid

The aim of this study was to assess the influence of season, farm management (organic, biodynamic, integrated, and conventional), and soil chemical, physical, and biological properties on gross nitrogen (N) fluxes and bacterial community structure in the semi-arid region of Western Australia. Moisture availability was the dominant factor mediating microbial activity and carbon (C) and N cycling under this climate. In general, microbial biomass N, dissolved organic N, and potentially mineralisable N were greater in organic and biodynamic than integrated and conventional soil. Our results indicate that greater silt and clay content in organic and biodynamic soil may also partly explain these differences in soil N pools, rather than management alone. Although plant-available N (NH4+ + NO3–) was greater in conventional soil, this was largely the result of higher NO3– production. Multiple linear modelling indicated that soil temperature, moisture, soil textural classes, pH, electrical conductivity (EC), and C and N pools were important in predicting gross N fluxes. Redundancy analysis revealed that bacterial community structure, assessed by denaturing gradient gel electrophoresis of 16S rDNA, was correlated with C and N pools and fluxes, confirming links between bacterial structure and function. Bacterial community structure was also correlated with soil textural classes and soil temperature but not soil moisture. These results indicate that across this semi-arid landscape, soil bacterial communities are relatively resistant to water stress.

Bacterial community structure in the rhizosphere of three cactus species from semi-arid highlands in central Mexico

2012 ◽  
Vol 101 (4) ◽  
pp. 891-904 ◽  
Author(s):  
J. Félix Aguirre-Garrido ◽  
Daniel Montiel-Lugo ◽  
César Hernández-Rodríguez ◽  
Gloria Torres-Cortes ◽  
Vicenta Millán ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Central Mexico ◽  
Semi Arid

scholarly journals Nitrogen Fertilizer Driven Bacterial Community Structure in a Semi-Arid Region of Northeast China

2021 ◽  
Vol 13 (21) ◽  
pp. 11967
Author(s):  
Meng Wang ◽  
Ling Wang ◽  
Qian Li ◽  
Hang Liu ◽  
Yuan Lin ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Community Structure ◽  
Bacterial Abundance ◽  
Structure Stability ◽  
N Application ◽  
N Cycle ◽  
Application Rates ◽  
Semi Arid

The soil nitrogen (N) cycle is an essential role of the biogeochemical cycle. Bacteria play an irreplaceable part in the soil N cycle, but the impact of different N gradients on bacterial communities remains unclear. The purpose of this research was to explore the bacterial abundance, community composition, and diversity under different N application rates in a water-limited area. We investigated the bacterial abundance, diversity, community composition, and structure under five different N gradients (0, 90, 150, 210, and 270 kg ha−1) using real-time quantitative PCR and high-throughput sequencing, and then explored bacterial functional groups with FAPROTAX. N application significantly affected bacterial abundance and community composition. Bacterial diversity was enhanced at low N application rates and reduced at higher N application rates. Principal coordinate analysis showed that bacterial community structure was separated into two groups between low N application rates and high N application rates; these differences in bacterial community structure may be driven by available nitrogen (AN). The results of FAPROTAX revealed that N application promoted the functions of Aerobic_nitrite_oxidation, Nitrate_reduction, and Aerobic_ammonia_oxidation, but inhibited the Nitrogen_fixation function of the bacterial community. The high N network caused the reduction of network structure stability. Our results revealed that N fertilizer driven bacterial community structure and soil nutrients were the main influential factors in the variation of bacterial community structure. We suggest that the optimal N application rate in this study may be approximately 150 kg ha−1, based on the variations of soil properties and bacterial community structure in semi-arid areas.

scholarly journals Maize root and shoot litter quality controls short-term CO<sub>2</sub> and N<sub>2</sub>O emissions and bacterial community structure of arable soil

2019 ◽  
Author(s):  
Pauline Sophie Rummel ◽  
Birgit Pfeiffer ◽  
Johanna Pausch ◽  
Reinhard Well ◽  
Dominik Schneider ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Litter Quality ◽  
Plant Litter ◽  
Maize Root ◽  
N2o Emissions ◽  
Community Structures ◽  
Root Litter ◽  
C And N

Abstract. Chemical composition of root and shoot litter controls decomposition and, subsequently, C availability for biological nitrogen transformation processes in soils. While aboveground plant residues have been proven to increase N2O emissions, studies on root litter effects are scarce. This study aimed (1) to evaluate how fresh maize root litter affects N2O emissions compared to fresh maize shoot litter, (2) to assess whether N2O emissions are related to the interaction of C and N mineralization from soil and litter, and (3) to analyze changes in soil microbial community structures related to litter input and N2O emissions. To obtain root and shoot litter, Maize plants (Zea mays L.) were cultivated with two N fertilizer levels in a greenhouse and harvested. A two-factorial 22-day laboratory incubation experiment was set up with soil from both N levels (N1, N2) and three litter addition treatments (Control, Root, Root+Shoot). We measured hourly CO2 and N2O fluxes, analyzed soil nitrate and water extractable organic C (WEOC) concentrations, and determined quality parameters of maize litter. Bacterial community structures were analyzed using 16S rRNA gene sequencing. Maize litter quality controlled NO3− and WEOC availability and decomposition related CO2 emissions. High bioavailability of maize shoot litter strongly increased CO2 and N2O emissions, while emissions induced by maize root litter remained low. We identified a strong positive correlation between cumulative CO2 and N2O emissions, supporting our hypothesis that litter quality affects denitrification by creating plant litter associated anaerobic microsites. The interdependency of C and N availability was validated by analyses of regression. Moreover, there was a strong positive interaction between soil NO3− and WEOC concentration resulting in much higher N2O emissions, when both NO3− and WEOC were available. A significant correlation was observed between total CO2 and N2O emissions, the soil bacterial community composition and the litter level, showing a clear separation of Root+Shoot samples of all remaining samples. Bacterial diversity decreased with higher N level and higher input of easily available C. Altogether, changes in bacterial community structure reflected degradability of maize litter with easily degradable C from maize shoot litter favoring fast growing C cycling and N reducing bacteria of the phyla Actinobacteria, Chloroflexi, Firmicutes and Proteobacteria.

scholarly journals Effects of Warming and Nitrogen Addition on the Soil Bacterial Community in a Subtropical Chinese Fir Plantation

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 861 ◽  
Author(s):  
Xie ◽  
Zhang ◽  
Cao ◽  
Liu ◽  
Xiong ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Southern China ◽  
N Cycling ◽  
Chinese Fir ◽  
N Addition ◽  
Soil Warming ◽  
Soil C ◽  
C And N

Soil warming has the potential to alter bacterial communities, affecting carbon (C) storage and nitrogen (N) cycling in forest ecosystems. We studied bacterial community changes by warming soil and adding two N-levels (40 and 80 kg N ha−1 year−1) for two years in a subtropical plantation of Chinese fir (Cunninghamia lanceolate (Lamb.) Hook) in southern China. Soil warming significantly changed the bacterial community structure, causing decreases in Proteobacteria and Acidobacteria, while increasing Actinobacteria and Chloroflexi. The high N addition had a greater impact on the bacterial community structure than the low N addition. Warming shifted the bacterial community towards oligotrophic taxa, while N addition could dilute this tendency. Results of the ecological networks indicated that warming resulted in a more complicated co-occurrence network and an increased interaction between different phylum communities, while N addition enhanced the cooperation within communities pertaining to the same phylum. The changes to the soil properties, typical catabolism enzymes, and plant growth also showed that soil warming and N addition accelerated the C and N cycles in the soil, and lead to an increased upward flow of N (from underground to aboveground) and decomposition rate of soil organic carbon (SOC). Overall, the results provided insights into the bacterial community and soil C and N cycling change at a subtropical plantation.

scholarly journals The Impact of the Inoculation of Phosphate-Solubilizing Bacteria Pantoea agglomerans on Phosphorus Availability and Bacterial Community Dynamics of a Semi-Arid Soil

2021 ◽  
Vol 9 (8) ◽  
pp. 1661
Author(s):  
Ilhem Saadouli ◽  
Amor Mosbah ◽  
Raoudha Ferjani ◽  
Panagiota Stathopoulou ◽  
Ioannis Galiatsatos ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Pantoea Agglomerans ◽  
Available P ◽  
Arid Soil ◽  
Phosphate Availability ◽  
Phosphate Solubilizing ◽  
The Impact ◽  
Semi Arid

The bacterial genus Pantoea has been widely evaluated as promising bacteria to increase phosphorus (P) availability in soil. The aim of this study was to characterize the phosphate solubilizing (PS) activity of a Pantoea agglomerans strain and to evaluate the impact of its application in a semi-arid soil on phosphate availability and structure of the bacterial communities as a whole. An incubation experiment under close-to-natural soil environmental conditions was conducted for 15 days at 30 °C. High-throughput sequencing of the bacterial 16S rRNA gene was used to characterize and to compare the bacterial community structure of P. agglomerans-inoculated soil with non-inoculated control. Furthermore, a qPCR-based method was developed for detection and quantification of the functional genes related to the expression of mineral phosphate solubilization (MPS) phenotype in P. agglomerans. The results showed that in vitro solubilization of Ca3(PO4)2 by P. agglomerans strain was very efficient (980 mg/L), and it was associated with a drop in pH due to the secretion of gluconic acid; these changes were concomitant with the detection of gdh and pqqC genes. Moreover, P. agglomerans inoculum application significantly increased the content of available P in semi-arid soil by 69%. Metagenomic analyses showed that P. agglomerans treatment modified the overall edaphic bacterial community, significantly impacting its structure and composition. In particular, during P. agglomerans inoculation the relative abundance of bacteria belonging to Firmicutes (mainly Bacilli class) significantly increased, whereas the abundance of Actinobacteria together with Acidobacteria and Chloroflexi phyla decreased. Furthermore, genera known for their phosphate solubilizing activity, such as Aneurinibacillus, Lysinibacillus, Enterococcus, and Pontibacter, were exclusively detected in P. agglomerans-treated soil. Pearson’s correlation analysis revealed that changes in soil bacterial community composition were closely affected by soil characteristics, such as pH and available P. This study explores the effect of the inoculation of P. agglomerans on the bacterial community structure of a semi-arid soil. The effectiveness in improving the phosphate availability and modification in soil bacterial community suggested that P. agglomerans represent a promising environmental-friendly biofertilizer in arid and semi-arid ecosystems.

Temporally invariable bacterial community structure in the Arabian Sea oxygen minimum zone

2014 ◽  
Vol 73 (1) ◽  
pp. 51-67 ◽  
Author(s):  
A Jain ◽  
M Bandekar ◽  
J Gomes ◽  
D Shenoy ◽  
RM Meena ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Arabian Sea ◽  
Oxygen Minimum Zone ◽  
Minimum Zone ◽  
Oxygen Minimum
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