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Chen H, Yang T, Xia Q, Bowman D, Williams D, Walker JT, Shi W. The extent and pathways of nitrogen loss in turfgrass systems: Age impacts. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 637-638:746-757. [PMID: 29758430 PMCID: PMC6064208 DOI: 10.1016/j.scitotenv.2018.05.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/07/2018] [Accepted: 05/04/2018] [Indexed: 05/25/2023]
Abstract
Nitrogen loss from fertilized turf has been a concern for decades, with most research focused on inorganic (NO3-) leaching. The present work examined both inorganic and organic N species in leachate and soil N2O emissions from intact soil cores of a bermudagrass chronosequence (1, 15, 20, and 109 years old) collected in both winter and summer. Measurements of soil N2O emissions were made daily for 3 weeks, while leachate was sampled once a week. Four treatments were established to examine the impacts of fertilization and temperature: no N, low N at 30 kg N ha-1, and high N at 60 kg N ha-1, plus a combination of high N and temperature (13 °C in winter or 33 °C in summer compared to the standard 23 °C). Total reactive N loss generally showed a "cup" pattern of turf age, being lowest for the 20 years old. Averaged across all intact soil cores sampled in winter and summer, organic N leaching accounted for 51% of total reactive N loss, followed by inorganic N leaching at 41% and N2O-N efflux at 8%. Proportional loss among the fractions varied with grass age, season, and temperature and fertilization treatments. While high temperature enhanced total reactive N loss, it had little influence on the partitioning of loss among dissolved organic N, inorganic N and N2O-N when C availability was expected to be high in summer due to rhizodeposition and root turnover. This effect of temperature was perhaps due to higher microbial turnover in response to increased C availability in summer. However when C availability was low in winter, warming might mainly affect microbial growth efficiency and therefore partitioning of N. This work provides a new insight into the interactive controls of warming and substrate availability on dissolved organic N loss from turfgrass systems.
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Affiliation(s)
- Huaihai Chen
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA; Environmental Sciences Division, National Exposure Research Laboratory, U.S. Environmental Protection Agency, RTP, NC, USA; Air Pollution Prevention and Control Division, National Risk Management Research Laboratory, U.S. Environmental Protection Agency, RTP, NC, USA
| | - Tianyou Yang
- College of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Qing Xia
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Daniel Bowman
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - David Williams
- Environmental Sciences Division, National Exposure Research Laboratory, U.S. Environmental Protection Agency, RTP, NC, USA
| | - John T Walker
- Air Pollution Prevention and Control Division, National Risk Management Research Laboratory, U.S. Environmental Protection Agency, RTP, NC, USA
| | - Wei Shi
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA.
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Baker BH, Kröger R, Brooks JP, Smith RK, Czarnecki JMP. Investigation of denitrifying microbial communities within an agricultural drainage system fitted with low-grade weirs. WATER RESEARCH 2015; 87:193-201. [PMID: 26414296 DOI: 10.1016/j.watres.2015.09.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 09/14/2015] [Accepted: 09/15/2015] [Indexed: 06/05/2023]
Abstract
Enhancing wetland characteristics in agricultural drainage ditches with the use of low-grade weirs, has been identified as a best management practice (BMP) to mitigate nutrient runoff from agriculture landscapes. A major objective of utilizing low-grade weirs as a BMP includes fostering environments suitable for the biogeochemical removal of nitrogen via denitrification. This study examined the spatial resolution of microbial communities involved in denitrification in agricultural drainage systems fitted with low-grade weirs. Appropriate sampling scales of microbial communities were investigated using 16S rRNA and denitrification functional genes nosZ, nirS, and nirK via quantitative polymerase chain reaction (qPCR) and terminal-restriction fragment length polymorphism (T-RFLP) analysis. Genes 16S rRNA, nosZ, and nirS were all successfully detected in soil samples, while nirK was below the detection limit throughout the study. Utilizing a combination of three sampling regimes (management, reach, catchment) was found to be effective in capturing microbial community patterns, as ANOVA results revealed nosZ gene abundance was significantly greater at the management rather than reach scale (p = 0.045; F = 3.311), although, no significant differences were observed in 16S rRNA or nirS between sampling scales (p > 0.05). A Pearson correlation matrix confirmed that 16S rRNA and nosZ gene abundances were positively correlated with soil carbon (C), nitrogen (N), and moisture, while nirS abundance was only positively correlated with soil C and soil moisture. This highlights the potential for wetland-like characteristics to be recovered in agricultural drainage systems, as weir proximity is observed to enhance soil moisture and conditions for N remediation. This study provides the basis for additional investigations of these unique environments in the Mississippi Alluvial Valley and a starting point for adaptive management to enhance agricultural drainage systems for microbial communities towards nutrient remediation goals.
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Affiliation(s)
- Beth H Baker
- Department of Wildlife, Fisheries and Aquaculture, MS, USA.
| | - Robert Kröger
- Department of Wildlife, Fisheries and Aquaculture, MS, USA
| | - John P Brooks
- United States Department of Agriculture-Agricultural Research Service, MS, USA
| | - Renotta K Smith
- United States Department of Agriculture-Agricultural Research Service, MS, USA
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Nitrosospira lacus sp. nov., a psychrotolerant, ammonia-oxidizing bacterium from sandy lake sediment. Int J Syst Evol Microbiol 2015; 65:242-250. [DOI: 10.1099/ijs.0.070789-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A Gram-negative, spiral-shaped, chemolithotrophic, ammonia-oxidizing bacterium, designated APG3T, was isolated into pure culture from sandy lake sediment collected from Green Lake, Seattle, WA, USA. Phylogenetic analyses based on the 16S rRNA gene sequence showed that strain APG3T belongs to cluster 0 of the genus
Nitrosospira
, which is presently not represented by described species, with
Nitrosospira multiformis
(cluster 3) as the closest species with a validly published name (identity of 98.6 % to the type strain). Strain APG3T grew at 4 °C but could not grow at 35 °C, indicating that this bacterium is psychrotolerant. Remarkably, the strain was able to grow over a wide range of pH (pH 5–9), which was greater than the pH range of any studied ammonia-oxidizing bacteria in pure culture. The DNA G+C content of the APG3T genome is 53.5 %, which is similar to that of
Nitrosospira multiformis
ATCC 25196T (53.9 %) but higher than that of
Nitrosomonas europaea
ATCC 19718 (50.7 %) and
Nitrosomonas eutropha
C71 (48.5 %). The average nucleotide identity (ANI) calculated for the genomes of strain APG3T and
Nitrosospira multiformis
ATCC 25196T was 75.45 %, significantly lower than the value of 95 % ANI that corresponds to the 70 % species-level cut-off based on DNA–DNA hybridization. Overall polyphasic taxonomy study indicated that strain APG3T represents a novel species in the genus
Nitrosospira
, for which the name Nitrosospira lacus sp. nov. is proposed (type strain APG3T = NCIMB 14869T = LMG 27536T = ATCC BAA-2542T).
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Changes in diversity and functional gene abundances of microbial communities involved in nitrogen fixation, nitrification, and denitrification in a tidal wetland versus paddy soils cultivated for different time periods. Appl Environ Microbiol 2011; 77:6109-16. [PMID: 21764972 DOI: 10.1128/aem.01751-10] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In many areas of China, tidal wetlands have been converted into agricultural land for rice cultivation. However, the consequences of land use changes for soil microbial communities are poorly understood. Therefore, we investigated bacterial and archaeal communities involved in inorganic nitrogen turnover (nitrogen fixation, nitrification, and denitrification) based on abundances and relative species richness of the corresponding functional genes along a soil chronosequence ranging between 50 and 2,000 years of paddy soil management compared to findings for a tidal wetland. Changes in abundance and diversity of the functional groups could be observed, reflecting the different chemical and physical properties of the soils, which changed in terms of soil development. The tidal wetland was characterized by a low microbial biomass and relatively high abundances of ammonia-oxidizing microbes. Conversion of the tidal wetlands into paddy soils was followed by a significant increase in microbial biomass. Fifty years of paddy management resulted in a higher abundance of nitrogen-fixing microbes than was found in the tidal wetland, whereas dominant genes of nitrification and denitrification in the paddy soils showed no differences. With ongoing rice cultivation, copy numbers of archaeal ammonia oxidizers did not change, while that of their bacterial counterparts declined. The nirK gene, coding for nitrite reductase, increased with rice cultivation time and dominated its functionally redundant counterpart, nirS, at all sites under investigation. Relative species richness showed significant differences between all soils with the exception of the archaeal ammonia oxidizers in the paddy soils cultivated for 100 and 300 years. In general, changes in diversity patterns were more pronounced than those in functional gene abundances.
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Links between ammonia oxidizer community structure, abundance, and nitrification potential in acidic soils. Appl Environ Microbiol 2011; 77:4618-25. [PMID: 21571885 DOI: 10.1128/aem.00136-11] [Citation(s) in RCA: 297] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ammonia oxidation is the first and rate-limiting step of nitrification and is performed by both ammonia-oxidizing archaea (AOA) and bacteria (AOB). However, the environmental drivers controlling the abundance, composition, and activity of AOA and AOB communities are not well characterized, and the relative importance of these two groups in soil nitrification is still debated. Chinese tea orchard soils provide an excellent system for investigating the long-term effects of low pH and nitrogen fertilization strategies. AOA and AOB abundance and community composition were therefore investigated in tea soils and adjacent pine forest soils, using quantitative PCR (qPCR), terminal restriction fragment length polymorphism (T-RFLP) and sequence analysis of respective ammonia monooxygenase (amoA) genes. There was strong evidence that soil pH was an important factor controlling AOB but not AOA abundance, and the ratio of AOA to AOB amoA gene abundance increased with decreasing soil pH in the tea orchard soils. In contrast, T-RFLP analysis suggested that soil pH was a key explanatory variable for both AOA and AOB community structure, but a significant relationship between community abundance and nitrification potential was observed only for AOA. High potential nitrification rates indicated that nitrification was mainly driven by AOA in these acidic soils. Dominant AOA amoA sequences in the highly acidic tea soils were all placed within a specific clade, and one AOA genotype appears to be well adapted to growth in highly acidic soils. Specific AOA and AOB populations dominated in soils at particular pH values and N content, suggesting adaptation to specific niches.
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The community composition of soil-denitrifying bacteria from a turfgrass environment. Res Microbiol 2010; 161:315-25. [DOI: 10.1016/j.resmic.2010.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 03/30/2010] [Accepted: 03/31/2010] [Indexed: 11/22/2022]
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