On the constructions of n-cycle permutations

Acid rain (AR), as a global environmental threat, has profoundly adverse effects on natural soil ecosystems. Microorganisms involved in the nitrogen (N) cycle regulate the global N balance and climate stabilization, but little is known whether and how AR influences the structure and complexity of these microbial communities. Herein, we conducted an intact soil core experiment by manipulating the acidity of simulated rain (pH 7.5 (control, CK) vs. pH 4.0 (AR)) in subtropical agricultural soil, to reveal the differences in the structure and complexity of soil nitrifying and denitrifying microbiota using Illumina amplicon sequencing of functional genes (amoA, nirS, and nosZ). Networks of ammonia-oxidizing archaea (AOA) and nirS-carrying denitrifiers in AR treatment were less complex with fewer nodes and lower connectivity, while network of nosZ-carrying denitrifiers in AR treatment had higher complexity and connectivity relative to CK. Supporting this, AR reduced the abundance of keystone taxa in networks of AOA and nirS-carrying denitrifiers, but increased the abundance of keystone taxa in nosZ-carrying denitrifiers network. However, AR did not alter the community structure of AOA, ammonia-oxidizing bacteria (AOB), nirS-, and nosZ-carrying denitrifiers. Moreover, AR did not change soil N2O emissions during the experimental period. AOB community structure significantly correlated with content of soil available phosphorus (P), while the community structures of nirS- and nosZ-carrying denitrifiers both correlated with soil pH and available P content. Soil N2O emission was mainly driven by the nirS-carrying denitrifiers. Our results present new perspective on the impacts of AR on soil N-cycle microbial network complexity and keystone taxa in the context of global changes.

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Estimates of Microbial Populations Involved in the N Cycle and their Activity in Water and Sediments of Fish Farming Ponds under Mono and Polyculture Systems in India

Internationale Revue der gesamten Hydrobiologie und Hydrographie ◽

10.1002/iroh.19830680409 ◽

1983 ◽

Vol 68 (4) ◽

pp. 581-590 ◽

Cited By ~ 7

Author(s):

B. B. Jana ◽

S. K. Roy

Keyword(s):

Fish Farming ◽

Microbial Populations ◽

N Cycle

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Carbon and nitrogen budgets of a winter rapeseed field in Estonia: a methodology for the quantification of all relevant pools and fluxes

10.5194/egusphere-egu21-15668 ◽

2021 ◽

Author(s):

Jordi Escuer-Gatius ◽

Krista Lõhmus ◽

Merrit Shanskiy ◽

Karin Kauer ◽

Hanna Vahter ◽

...

Keyword(s):

Mass Balance ◽

Environmental Parameters ◽

Balance Method ◽

Nitrogen Budgets ◽

N Cycle ◽

Carbon And Nitrogen ◽

Mass Balance Method ◽

C Cycle ◽

Winter Rapeseed ◽

C And N

Agricultural activities can have several adverse impacts on the environment; such as important greenhouse gas (GHG) emissions. To implement effective mitigation measures and create effective policies, it is necessary to know the full carbon and nitrogen budgets of agro-ecosystems. However, very often, information regarding the pools or fluxes involved in the carbon and nitrogen cycles is limited, and essential complementary data needed for a proper interpretation is lacking.This study aimed to quantify all the relevant pools and fluxes of a winter rapeseed, a widely spread crop in the Europe and Baltic regions. The N2O and CH4 fluxes were measured weekly using the closed static chamber method from August 2016 to August 2017 in a winter rapeseed field in Central Estonia. Additionally, nutrient leaching and soil chemical parameters, as well as environmental parameters like soil moisture, electrical conductivity and temperature were monitored. At the end of the season, the rapeseed and weed biomasses were collected, weighed and analyzed. The remaining relevant fluxes in the N cycle were calculated using various non-empirical methods: NH3 volatilization was estimated from slurry and environmental parameters, N deposition and NOx emissions were obtained from national reports, and N2 emissions were calculated with the mass balance method. Regarding the C cycle, gross primary production (GPP) of the rapeseed field was also calculated by the mass balance method. Simultaneously, for comparison and validation purposes, GPP was estimated from the data provided by MOD17A2H v006 series from NASA, and N2 was estimated from the measured emissions of N2O using the N2:N2O ratio calculated from the DAYCENT model equations.N2 emissions and GPP were the biggest fluxes in the N and C cycles, respectively. N2 emissions were followed by N extracted with plant biomass in the N cycle, while in the carbon cycle soil and plant respiration and NPP were the highest fluxes after GPP. The carbon balance was positive at the soil level, with a net increase in soil carbon during the period, mainly due to GPP carbon capture. Contrarily, the nitrogen balance resulted in a net loss of N due to the losses related to gaseous emissions (N2 and N2O) and leaching.To conclude, it was possible to close the C and N budgets, despite the inherent difficulties of estimating the different C and N environmental pools and fluxes, and the uncertainties deriving from some of the fluxes estimations.

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The soil N cycle: new insights and key challenges

SOIL ◽

10.5194/soil-1-235-2015 ◽

2015 ◽

Vol 1 (1) ◽

pp. 235-256 ◽

Cited By ~ 87

Author(s):

J. W. van Groenigen ◽

D. Huygens ◽

P. Boeckx ◽

Th. W. Kuyper ◽

I. M. Lubbers ◽

...

Keyword(s):

N Cycling ◽

Greenhouse Gas Mitigation ◽

Future Research ◽

N Fixation ◽

Gaseous Emissions ◽

Soil N ◽

Personal View ◽

Total N ◽

N Cycle ◽

Soil N Cycle

Abstract. The study of soil N cycling processes has been, is, and will be at the centre of attention in soil science research. The importance of N as a nutrient for all biota; the ever-increasing rates of its anthropogenic input in terrestrial (agro)ecosystems; its resultant losses to the environment; and the complexity of the biological, physical, and chemical factors that regulate N cycling processes all contribute to the necessity of further understanding, measuring, and altering the soil N cycle. Here, we review important insights with respect to the soil N cycle that have been made over the last decade, and present a personal view on the key challenges of future research. We identify three key challenges with respect to basic N cycling processes producing gaseous emissions: 1. quantifying the importance of nitrifier denitrification and its main controlling factors; 2. characterizing the greenhouse gas mitigation potential and microbiological basis for N2O consumption; 3. characterizing hotspots and hot moments of denitrification Furthermore, we identified a key challenge with respect to modelling: 1. disentangling gross N transformation rates using advanced 15N / 18O tracing models Finally, we propose four key challenges related to how ecological interactions control N cycling processes: 1. linking functional diversity of soil fauna to N cycling processes beyond mineralization; 2. determining the functional relationship between root traits and soil N cycling; 3. characterizing the control that different types of mycorrhizal symbioses exert on N cycling; 4. quantifying the contribution of non-symbiotic pathways to total N fixation fluxes in natural systems We postulate that addressing these challenges will constitute a comprehensive research agenda with respect to the N cycle for the next decade. Such an agenda would help us to meet future challenges on food and energy security, biodiversity conservation, water and air quality, and climate stability.

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Compounded Disturbance Chronology Modulates the Resilience of Soil Microbial Communities and N-Cycle Related Functions

Frontiers in Microbiology ◽

10.3389/fmicb.2018.02721 ◽

2018 ◽

Vol 9 ◽

Cited By ~ 6

Author(s):

Kadiya Calderón ◽

Laurent Philippot ◽

Florian Bizouard ◽

Marie-Christine Breuil ◽

David Bru ◽

...

Keyword(s):

Microbial Communities ◽

Soil Microbial Communities ◽

N Cycle ◽

Soil Microbial

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C and N cycle monitoring under Quercus castaneifolia plantation

Forest Ecology and Management ◽

10.1016/j.foreco.2018.05.060 ◽

2018 ◽

Vol 427 ◽

pp. 26-36 ◽

Cited By ~ 10

Author(s):

Mohammad Kazem Parsapour ◽

Yahya Kooch ◽

Seyed Mohsen Hosseini ◽

Seyed Jalil Alavi

Keyword(s):

N Cycle ◽

C And N ◽

Cycle Monitoring

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The Importance of the Microbial N Cycle in Soil for Crop Plant Nutrition

Advances in Applied Microbiology ◽

10.1016/bs.aambs.2015.09.001 ◽

2015 ◽

pp. 45-71 ◽

Cited By ~ 21

Author(s):

Penny R. Hirsch ◽

Tim H. Mauchline

Keyword(s):

Plant Nutrition ◽

Crop Plant ◽

N Cycle ◽

Microbial N

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Renewable N-cycle catalysis

Trends in Chemistry ◽

10.1016/j.trechm.2021.04.010 ◽

2021 ◽

Author(s):

Simson Wu ◽

Shik Chi Edman Tsang

Keyword(s):

N Cycle

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Nitrogen Cycling

Structure and Function of an Alpine Ecosystem ◽

10.1093/oso/9780195117288.003.0019 ◽

2001 ◽

Author(s):

Melany C. Fisk ◽

Paul D. Brooks

Keyword(s):

Spatial Variation ◽

Water Availability ◽

Growing Season ◽

N Cycling ◽

Alpine Tundra ◽

N Transformations ◽

Cold Temperatures ◽

Niwot Ridge ◽

N Cycle ◽

Large N

In this chapter, we discuss the current understanding of internal N cycling, or the flow of N through plant and soil components, in the Niwot Ridge alpine ecosystem. We consider the internal N cycle largely as the opposing processes of uptake and incorporation of N into organic form and mineralization of N from organic to inorganic form. We will outline the major organic pools in which N is stored and discuss the transfers of N into and from those pools. With a synthesis of information regarding the various N pools and relative turnover of N through them, we hope to provide greater understanding of the relative function of different components of the alpine N cycle. Because of the short growing season, cold temperatures, and water regimes tending either toward very dry or very wet extremes, the alpine tundra is not a favorable ecosystem for either production or decomposition. Water availability, temperature, and nutrient availability (N in particular) all can limit alpine plant growth (chapter 9). Cold soils also inhibit decomposition so that N remains bound in organic matter and is unavailable for plant uptake (chapter 11). Consequently, N cycling in the alpine often is presumed to be slow and conservative (Rehder 1976a, 1976b; Holzmann and Haselwandter 1988). Nonetheless, studies reveal large spatial variation in primary production and N cycling in alpine tundra across gradients of snowpack accumulation, growing season water availability, and plant species composition (May and Webber, 1982, Walker et al., 1994, Bowman, 1994, Fisk et al. 1998; chapter 9). Furthermore, evidence for relatively large N transformations under seasonal snowcover (Brooks et al., 1995a, 1998) and maintenance of high microbial biomass in frozen soils (Lipson et al. 1999a) provide a complex temporal component of N cycling on Niwot Ridge. Our discussion of N cycling on Niwot Ridge will focus on two main points: first, the spatial variation in N turnover in relation to snowpack regimes and plant community distributions; and second, the temporal variability of N transformations during both snow-free and snow-covered time periods.

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Variations of belowground C and N cycling between arbuscular mycorrhizal and ectomycorrhizal forests across China

Soil Research ◽

10.1071/sr19377 ◽

2020 ◽

Vol 58 (5) ◽

pp. 441 ◽

Cited By ~ 1

Author(s):

Jiwei Li ◽

Zhouping Shangguan ◽

Lei Deng

Keyword(s):

Soil Respiration ◽

Forest Ecosystems ◽

Arbuscular Mycorrhizal ◽

N Cycling ◽

Microbial Biomass C ◽

N Cycle ◽

Positive Effects ◽

Litter Input ◽

C And N ◽

C And N Cycling

Forests associating with arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi may have distinct belowground carbon (C) and nitrogen (N) cycle processes. However, there are little available data providing evidence for the effects of trees associating with mycorrhizal type on belowground C and N cycling in forest ecosystems in China. Here, we collected a database of 26 variables related to belowground C and N cycling from 207 studies covering 209 sampling sites in China, to better understand the variations in belowground C and N cycling between the two mycorrhizal types in forest ecosystems along a climatic gradient. The AM forests had significantly lower soil total C and N contents, and soil microbial biomass C and N, than ECM forests, probably due to differences in litter quality (N and C/N) between AM and ECM forest types. In contrast, AM forests had significantly higher litter input, litter decomposition and soil respiration than ECM forests. Temperature and precipitation had significant positive effects on litter input and decomposition, soil total C and N contents, and soil respiration in AM and ECM forests. Overall, our results indicated that mycorrhizal type strongly affected belowground C and N cycle processes in forest ecosystems. Moreover, AM forests are likely more sensitive and ECM forests have a greater ability to adapt to global climate change.

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