Uranium stability in a large wetland soil core probed by electron acceptors, carbonate amendments and wet-dry cycling in a long-term lysimeter experiment

2021 ◽  
pp. 149783
Author(s):  
Marietta Straub ◽  
Jasquelin Peña ◽  
Virginie Flury ◽  
Pascal Froidevaux
Keyword(s):  
Electron Acceptors ◽  
Wetland Soil ◽  
Soil Core ◽  
Lysimeter Experiment

scholarly journals Geobacter bemidjiensis sp. nov. and Geobacter psychrophilus sp. nov., two novel Fe(III)-reducing subsurface isolates

2005 ◽  
Vol 55 (4) ◽  
pp. 1667-1674 ◽  
Author(s):  
Kelly P. Nevin ◽  
Dawn E. Holmes ◽  
Trevor L. Woodard ◽  
Erich S. Hinlein ◽  
David W. Ostendorf ◽  
...  
Keyword(s):  
Type Strain ◽  
Novel Species ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Amorphous Iron ◽  
Gram Negative ◽  
Subsurface Sediments ◽  
Curved Rods ◽  
A Site

Fe(III)-reducing isolates were recovered from two aquifers in which Fe(III) reduction is known to be important. Strain BemT was enriched from subsurface sediments collected in Bemidji, MN, USA, near a site where Fe(III) reduction is important in aromatic hydrocarbon degradation. Strains P11, P35T and P39 were isolated from the groundwater of an aquifer in Plymouth, MA, USA, in which Fe(III) reduction is important because of long-term inputs of acetate as a highway de-icing agent to the subsurface. All four isolates were Gram-negative, slightly curved rods that grew best in freshwater media. Strains P11, P35T and P39 exhibited motility via means of monotrichous flagella. Analysis of the 16S rRNA and nifD genes indicated that all four strains are δ-proteobacteria and members of the Geobacter cluster of the Geobacteraceae. Differences in phenotypic and phylogenetic characteristics indicated that the four isolates represent two novel species within the genus Geobacter. All of the isolates coupled the oxidation of acetate to the reduction of Fe(III) [iron(III) citrate, amorphous iron(III) oxide, iron(III) pyrophosphate and iron(III) nitrilotriacetate]. All four strains utilized ethanol, lactate, malate, pyruvate and succinate as electron donors and malate and fumarate as electron acceptors. Strain BemT grew fastest at 30 °C, whereas strains P11, P35T and P39 grew equally well at 17, 22 and 30 °C. In addition, strains P11, P35T and P39 were capable of growth at 4 °C. The names Geobacter bemidjiensis sp. nov. (type strain BemT=ATCC BAA-1014T=DSM 16622T=JCM 12645T) and Geobacter psychrophilus sp. nov. (strains P11, P35T and P39; type strain P35T=ATCC BAA-1013T=DSM 16674T=JCM 12644T) are proposed.

Nondestructive Sampling to Monitor Macrophomina phaseolina Root Colonization in Overwintering Stevia

2021 ◽  
Author(s):  
Layne W. Rogers ◽  
Alyssa M. Koehler
Keyword(s):  
Root Colonization ◽  
Root Zone ◽  
Macrophomina Phaseolina ◽  
Field Trials ◽  
Soil Core ◽  
Climate Data ◽  
Sample Weight ◽  
The Family ◽  
Soil Temperatures

Macrophomina phaseolina is a soilborne fungal pathogen in the family Botryosphaeriaceae. Microsclerotia of M. phaseolina were first observed at the base of overwintering stevia stems in North Carolina in spring 2016. Previous studies utilized destructive sampling methods to monitor M. phaseolina in stevia fields; however, these methods are not feasible for long-term monitoring of disease in a perennial system. In the current study, nondestructive root soil-core sampling was conducted during overwintering months, from October 2018 to January 2020, to monitor M. phaseolina root colonization in stevia in Rocky Mount, NC. Two-inch-diameter soil cores were collected through the root zone, and fresh weight of roots was recorded for each soil core. M. phaseolina recovery was evaluated by examining mycelial growth from roots plated onto potato dextrose agar. There was no significant effect of sample weight on M. phaseolina across all dates, but there was one date for which sample weight had a significant effect on recovery (P = 0.01; α = 0.05). For both recovery and sample weight, sampling date was a significant predictor (P = 1.68e-5 and P = 0.0389, respectively; α = 0.05). Weather and climate data revealed that dates with no M. phaseolina recovery had lowest mean air and soil temperatures and the greatest number of days below freezing in the month prior to sampling. In separate sampling years, October sampling dates had the highest recovery of M. phaseolina. Future field trials should determine if October samplings can predict survival and vigor of reemerging stevia plants.

Long-term grazing effects on soil-atmosphere exchanges of CO2, CH4 and N2O at different grasslands in Inner Mongolia: A soil core study

2019 ◽  
Vol 105 ◽  
pp. 316-328 ◽  
Author(s):  
Weiwei Chen ◽  
Xunhua Zheng ◽  
Benjamin Wolf ◽  
Zhisheng Yao ◽  
Chunyan Liu ◽  
...  
Keyword(s):  
Inner Mongolia ◽  
Soil Core ◽  
Grazing Effects ◽  
Soil Atmosphere ◽  
Core Study ◽  
Ch4 And N2o

A long-term lysimeter experiment to investigate the environmental dispersion of the herbicide chloridazon and its metabolites—comparison of lysimeter types

2015 ◽  
Vol 16 (3) ◽  
pp. 1032-1045 ◽  
Author(s):  
Andrea Schuhmann ◽  
Oliver Gans ◽  
Stefan Weiss ◽  
Johann Fank ◽  
Gernot Klammler ◽  
...  
Keyword(s):  
Lysimeter Experiment

scholarly journals Long-Term Persistence and Leaching of Escherichia coli in Temperate Maritime Soils

2009 ◽  
Vol 76 (5) ◽  
pp. 1449-1455 ◽  
Author(s):  
Fiona P. Brennan ◽  
Vincent O'Flaherty ◽  
Gaelene Kramers ◽  
Jim Grant ◽  
Karl G. Richards
Keyword(s):  
Escherichia Coli ◽  
Soil Type ◽  
Preferential Flow ◽  
Pathogenic Microorganisms ◽  
E Coli ◽  
Natural Rainfall ◽  
Lysimeter Experiment ◽  
Effect Of Treatment

ABSTRACT Enteropathogen contamination of groundwater, including potable water sources, is a global concern. The spreading on land of animal slurries and manures, which can contain a broad range of pathogenic microorganisms, is considered a major contributor to this contamination. Some of the pathogenic microorganisms applied to soil have been observed to leach through the soil into groundwater, which poses a risk to public health. There is a critical need, therefore, for characterization of pathogen movement through the vadose zone for assessment of the risk to groundwater quality due to agricultural activities. A lysimeter experiment was performed to investigate the effect of soil type and condition on the fate and transport of potential bacterial pathogens, using Escherichia coli as a marker, in four Irish soils (n = 9). Cattle slurry (34 tonnes per ha) was spread on intact soil monoliths (depth, 1 m; diameter, 0.6 m) in the spring and summer. No effect of treatment or the initial soil moisture on the E. coli that leached from the soil was observed. Leaching of E. coli was observed predominantly from one soil type (average, 1.11 � 0.77 CFU ml−1), a poorly drained Luvic Stagnosol, under natural rainfall conditions, and preferential flow was an important transport mechanism. E. coli was found to have persisted in control soils for more than 9 years, indicating that autochthonous E. coli populations are capable of becoming naturalized in the low-temperature environments of temperate maritime soils and that they can move through soil. This may compromise the use of E. coli as an indicator of fecal pollution of waters in these regions.

Root biomass in timothy and red clover leys estimated by soil coring and mesh bags

1989 ◽  
Vol 113 (2) ◽  
pp. 241-247 ◽  
Author(s):  
E. Steen
Keyword(s):  
Root Biomass ◽  
Red Clover ◽  
Phleum Pratense ◽  
Root Decomposition ◽  
Soil Core ◽  
Soil Cores ◽  
Medium Term ◽  
Short Term ◽  
Mesh Bags

SUMMARYRoot biomass of timothy grass (Phleum pratense L.), at low and high N fertilization rates, and of red clover (Trifolium pratense L.) were estimated with soil cores and in mesh bags in a field trial on a sandy loam in central Sweden. First and second full-harvest year leys were sampled three times each year from May to October. Mesh bags were inserted in the soil in autumn shortly after sowing (longterm bags); in spring and autumn of the first year and in spring of the second year (medium-term bags); and every third month during both years (short-term bags). Mesh bags of each type were sampled when the soil cores were taken.Root biomass in the long-term bags was generally about the same as that in the soil cores, but taproot biomass in the clover crop was underestimated in the bags. In the grass plots, differences between soil cores and mesh bags were probably caused by ingrowth of weed roots in bags and by larger root biomass in plant rows than between rows. If soil cores and long-term mesh bags are sampled in exactly the same way identical estimates of biomass should be obtained.Root biomass in short-term and medium-term bags was about the same as that in the soil cores and long-term bags on many of the sampling occasions. Thus a stable level of biomass was reached in a rather short time, i.e. after 3 months or less. Then root production, root mortality and root decomposition occurred simultaneously at a fairly constant level.The bags did not contain residues from earlier crops, which reduced the amount of separation work necessary. The absence of crop residues in the bags did not seem to affect root biomass.The mesh bag method is a useful alternative to soil core sampling for studying root biomass and root dynamics in perennial and annual crops. However, the bags must be inserted into the soil just after sowing and they must be placed in, as well as between, plant rows.

Long-term salinity development in a lysimeter experiment

1997 ◽  
Vol 34 (1) ◽  
pp. 47-55 ◽  
Author(s):  
J.W. Van Hoorn ◽  
N. Katerji ◽  
A. Hamdy
Keyword(s):  
Lysimeter Experiment

scholarly journals Effects of Parent Material and Land Use on the Variability of Available Cu in a Wetland Soil under Long-Term Farming System

2019 ◽  
pp. 43-53
Keyword(s):  
Land Use ◽  
Crop Production ◽  
Dynamic Equilibrium ◽  
Mineral Fertilizer ◽  
Clay Content ◽  
Farming Systems ◽  
Parent Material ◽  
Wetland Soils ◽  
Wetland Soil

The study was carried out in the dry season to evaluate the variation in available Cu in wetland soil under long-term farming systems. Twenty four surface (0-20 cm) composite soil samples of acidic nature were obtained and analyzed for available Cu in the soils using five extractants (0.01M HCl, Coca-cola, 0.05M EDTA, 0.05M DTPA, and 1N NH4OAc) respectively. Some important soil char- acteristics like soil texture, pH, SOM, and ECEC were also determined and corre- lated with the extractable Cu. The result shows that the content of available Cu varied significantly from 1.72-10.76 mg kg-1 by DTPA and Coca-cola methods, and these were rated from low to moderate, respectively. The study further shows that, the comparative extraction capacity of these extractants followed the order: Coca-Cola > O.1N HCl > 0.05M EDTA > NH4OAc > 0.005M DTPA. The wide variability of the available Cu in the wetland soils under long-term farming sug- gests that the availability of Cu in the soil are haply influenced by the agricultural locations, type of land use systems and soil parent materials, respectively. Corre- lation data also indicated that the fractions of Cu by different extractants were in a state of dynamic equilibrium and dependent were on pH, organic matter, ECEC, and clay content. The marginally Cu content of the wetland soils suggests that the use of integrated organo-mineral fertilizer with copper sulphate com- pound (CuSO4.5H2O) is required to boost the soil Cu and hence increased crop production.

scholarly journals Modification of methane oxidation pathways during long-term incubations of methanic lake sediments

2021 ◽  
Author(s):  
Hanni Vigderovich ◽  
Werner Eckert ◽  
Michal Elul ◽  
Maxim Rubin-Blum ◽  
Marcus Elvert ◽  
...  
Keyword(s):  
Lake Sediments ◽  
Carbon Isotope ◽  
Iron Oxides ◽  
Methane Oxidation ◽  
Electron Acceptors ◽  
Anaerobic Oxidation Of Methane ◽  
Methanotrophic Bacteria ◽  
Oxidation Of Methane ◽  
Isotope Measurements

Abstract. Anaerobic oxidation of methane (AOM) is one of the major processes limiting the release of the greenhouse gas methane from natural environments. In Lake Kinneret sediments, iron-coupled AOM (Fe-AOM) was suggested to play a substantial role (10–15 % relative to methanogenesis) in the methanic zone (> 20 cm sediment depth), based on geochemical profiles and experiments on fresh sediments. Apparently, the oxidation of methane is mediated by a combination of mcr gene bearing archaea and aerobic bacterial methanotrophs. Here we aimed to investigate the survival of this complex microbial interplay under controlled conditions. We followed the AOM process during long-term (~18 months) anaerobic slurry experiments of these methanic sediments with two stages of incubations and additions of 13C-labeled methane, multiple electron acceptors and inhibitors. After these incubation stages carbon isotope measurements in the dissolved inorganic pool still showed considerable AOM (3–8 % relative to methanogenesis). Specific lipid carbon isotope measurements and metagenomic analyses indicate that after the prolonged incubation aerobic methanotrophic bacteria were no longer involved in the oxidation process, whereas mcr gene bearing archaea were most likely responsible for oxidizing the methane. Humic substances and iron oxides are likely electron acceptors to support this oxidation, whereas sulfate, manganese, nitrate, and nitrite did not support the AOM in these methanic sediments. Our results suggest in the natural lake sediments methanotrophic bacteria are responsible for part of the methane oxidation by the reduction of combined micro levels of oxygen and iron oxides in a cryptic cycle, while the rest of the methane is converted by reverse methanogenesis. After long-term incubation, the latter prevails without bacterial methanotropic activity and with a different iron reduction pathway.

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