The Experts below are selected from a list of 219 Experts worldwide ranked by ideXlab platform
Gilles Pinay - One of the best experts on this subject based on the ideXlab platform.
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respective roles of fe oxyhydroxide dissolution ph changes and sediment inputs in dissolved phosphorus release from wetland soils under anoxic conditions
Geoderma, 2019Co-Authors: Sen Gu, Gerard Gruau, Remi Dupas, Patrice Petitjean, Qingman Li, Gilles PinayAbstract:The development of anoxic conditions in riparian wetland (RW) soils is widely known to release dissolved phosphorus (DP), but the respective roles of reductive dissolution of Fe-oxyhydroxide, pH changes and sediment inputs in this release remain debated. This study aimed to identify and quantify these respective roles via laboratory anaerobic/aerobic Incubation of RW soils with and without the addition of sediment. The investigated soils came from two RWs with contrasting P status and organic matter (OM) content in their soils, while the added sediment carne from an adjacent cultivated field. Results showed that the amount and speciation of the DP released during anaerobic/aerobic Incubations were controlled by soil P status and soil OM content. During anaerobic Incubation, DP release in the soil with high extractable P and low OM contents was controlled by reductive dissolution of Fe-oxyhydroxides (83%), whereas that released in the soil with low extractable P and high OM contents was controlled by an increase in pH (88%). Anaerobic Incubation of a mixture of eroded sediments and RW soils increased the release of DP, dissolved organic carbon and Fe(11) (by 16%, 4% and 18%, respectively) compared to the simple addition of the amounts released during their separate Incubations. Management practices should decrease soil erosion from upland fields to avoid deposition of P-rich sediments on RW soils. Management efforts should focus preferentially on RWs whose Fe:P molar ratios in the soil solution during reduction are the lowest, since they indicate a high risk that the DP released will be transferred to watercourses.
Bo Barker Jorgensen - One of the best experts on this subject based on the ideXlab platform.
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anoxic Incubation of sediment in gas tight plastic bags a method for biogeochemical process studies
Marine Ecology Progress Series, 2000Co-Authors: Jens Wurgler Hansen, Bo Thamdrup, Bo Barker JorgensenAbstract:Incubation of sediment in gas-tight plastic bags is described as a method for experimental studies of biogeochemical processes. Sediment Incubation in these bags allows time-course experiments to be conducted on homogenised sediment without dilution, continuous stirring, or gaseous head-space. Consequently, bag Incubations of sediment combine the advantage of low heterogeneity in slurry Incubations with the more natural conditions in jar and whole-core Incubations. The bag material is a transparent laminated plastic comprised of Nylon, ethylenevinyl alcohol, and polyethylene with a low permeability for the studied gases: O 2 , CO 2 , H 2 S, CH 4 , N 2 , H 2 , and He. Estimated fluxes of biologically active gases through the plastic bag during sediment Incubation were insignificant compared to rates of microbial processes and to gas concentrations in coastal sediments. An exception was CH 4 , for which process calculations should include a correction for the exchange of CH 4 during Incubation. Sulphate reduction rates measured in intact sediment cores and in sediment sectioned and incubated in the bags showed similar profiles in 3 coastal sediments with oxygen penetrations from a few millimetres to 1 cm. In the most reduced sediment, whole-core and bagbased depth-integrated rates were the same while bag-rates exceeded whole-core rates by 1.4- and 3.2-fold in the intermediate and the most oxidised sediment, respectively. The differences may be related to the interruption of the biomediated transport of oxidants and the decay of fauna in the bag Incubations.
Samuel Abiven - One of the best experts on this subject based on the ideXlab platform.
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leaching of soils during laboratory Incubations does not affect soil organic carbon mineralisation but solubilisation
PLOS ONE, 2017Co-Authors: Beatriz Gonzalezdominguez, Mirjam S Studer, Frank Hagedorn, Pascal A Niklaus, Samuel AbivenAbstract:Laboratory soil Incubations provide controlled conditions to investigate carbon and nutrient dynamics; however, they are not free of artefacts. As carbon and nitrogen cycles are tightly linked, we aimed at investigating whether the Incubation-induced accumulation of mineral nitrogen (Nmin) biases soil organic carbon (SOC) mineralisation. For this, we selected two soils representative of the C:N ratio values found in European temperate forests, and applied two Incubation systems: 'closed' beakers and 'open' microlysimeters. The latter allowed leaching the soil samples during the Incubation. By the end of the 121-day experiment, the low C:N soil significantly accumulated more Nmin in beakers (5.12 g kg-1 OC) than in microlysimeters (3.00 g kg-1 OC) but there was not a significant difference in SOC mineralisation at any point of the experiment. On the other hand, Nmin did not accumulate in the high C:N soil but, by the end of the experiment, leaching had promoted 33.9% more SOC solubilisation than beakers. Therefore, we did not find evidence that Incubation experiments introduce a bias on SOC mineralisation. This outcome strengthens results from soil Incubation studies.
José L. Tadeo - One of the best experts on this subject based on the ideXlab platform.
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influence of the laboratory Incubation method on chlorotoluron and terbutryn degradation in soil
Journal of Agricultural and Food Chemistry, 1997Co-Authors: Yolanda Lechón, Consuelo Sanchezbrunete, José L. TadeoAbstract:Degradation of the herbicides chlorotoluron and terbutryn was assayed using three different Incubation systems: columns of undisturbed soil, columns packed with sieved soil, and flasks. Two different soils were employed, a sandy loam (A) and a loam soil (B), and different temperature (4-32 °C) and moisture content (7-13%) conditions were assayed. Dissipation of both herbicides in soil A for treatment T2 (25 °C and 10% of moisture content) was significantly different in the three different Incubation systems assayed. In the case of soil B, with lower organic matter content, the obtained half-lives for treatment T2 were statistically indistinguishable in all the Incubation systems, with the exception of the flask Incubation of terbutryn. Incubation in packed cores generally yielded longer half-lives than flask Incubations in all the other treatments for both soils and both compounds. Differences among Incubation systems were greater with terbutryn than with chlorotoluron, which has a lower sorption coefficient.
Nicolas Bernet - One of the best experts on this subject based on the ideXlab platform.
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The effect of Incubation conditions on the laboratory measurement of the methane producing capacity of livestock wastes
Bioresource Technology, 2008Co-Authors: Fabien Vedrenne, Fabrice Béline, Patrick Dabert, Nicolas BernetAbstract:The effects of Incubations conditions (dilution, mixing, Incubation time and inoculum amount and origin) on the determination of the maximum methane producing capacity (B0) from various livestock slurries were evaluated. For this purpose, the methane yields of different livestock slurries were determined using batch anaerobic Incubations performed at 30 [degree sign]C as regard these different conditions. The B0 and the methane (CH4) generation as a function of time were used to study the processes and to determine the best Incubation conditions. Methanogenesis was identified as the major rate-limiting step during the anaerobic degradation of slurries, probably due to inhibition by volatile fatty acids. In some cases, high free NH3 concentrations were suspected to inhibit the hydrolysis process. The addition of inoculum and/or the dilution of the substrate reduced the inhibition and allowed to reach the B0 more rapidly. However, the addition of inoculum must be minimized to reduce the possible errors made by considering a similar production by the inoculum with and without the substrate. All experiments performed during this study allowed to define the Incubation conditions required for the determination of the B0 from livestock slurries. Applying these conditions, the B0 values determined for swine slurries varied from 244 to 343 L , from 204 to 296 L for dairy cattle slurries and equalled 386 and 319 L respectively for calves and duck slurries.
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the effect of Incubation conditions on the laboratory measurement of the methane producing capacity of livestock wastes
Bioresource Technology, 2008Co-Authors: Fabien Vedrenne, Fabrice Béline, Patrick Dabert, Nicolas BernetAbstract:The effects of Incubations conditions (dilution, mixing, Incubation time and inoculum amount and origin) on the determination of the maximum methane producing capacity (B(0)) from various livestock slurries were evaluated. For this purpose, the methane yields of different livestock slurries were determined using batch anaerobic Incubations performed at 30 degrees C as regard these different conditions. The B(0) and the methane (CH(4)) generation as a function of time were used to study the processes and to determine the best Incubation conditions. Methanogenesis was identified as the major rate-limiting step during the anaerobic degradation of slurries, probably due to inhibition by volatile fatty acids. In some cases, high free NH(3) concentrations were suspected to inhibit the hydrolysis process. The addition of inoculum and/or the dilution of the substrate reduced the inhibition and allowed to reach the B(0) more rapidly. However, the addition of inoculum must be minimized to reduce the possible errors made by considering a similar production by the inoculum with and without the substrate. All experiments performed during this study allowed to define the Incubation conditions required for the determination of the B(0) from livestock slurries. Applying these conditions, the B(0) values determined for swine slurries varied from 244 to 343L CH(4)kg V(added)(-1), from 204 to 296L CH(4)kg V(added)(-1) for dairy cattle slurries and equalled 386 and 319L CH(4)kg VS(added)(-1) respectively for calves and duck slurries.
