The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Baoqing Shan - One of the best experts on this subject based on the ideXlab platform.
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phosphorus transformations at the sediment water interface in shallow freshwater ecosystems caused by decomposition of Plant Debris
Chemosphere, 2018Co-Authors: Wenqiang Zhang, Xin Meng, Wenzhong Tang, Baoqing ShanAbstract:Abstract We studied the processes and mechanisms that drove phosphorus (P) release and transformations at the sediment-water interface (SWI) because of the decomposition of Plant Debris. The results showed that, as the simulation time increased, the pH, dissolved oxygen (DO), and oxidation reduction potential (ORP) in Duckweed+Sediment+Water (DWS) and Duckweed+Water (DW) initially decreased and then increased before stabilizing. Changes in the physicochemical characteristics affect the microhabitat and the release and transformations of P at the SWI. The initial flux of total P (TP), total dissolved phosphorus (TDP), and soluble reactive phosphorus (SRP) was 886, 515, and 441 mg m−2 d−1 in DWS and 626, 376, and 330 mg m−2 d−1 in DW, respectively. As the Plant Debris decomposed, the fluxes of TP, TDP, and SRP decreased, and after 11 days, the fluxes remained at around 0 mg m−2 d−1. The dissolved organic phosphorus (DOP) flux followed different trends in DWS and DW, and increased first to a maximum of 285 and 109 mg m−2 d−1, respectively, by day 6. The results of this study indicate that Plant Debris decomposition drive P transformations at the SWI in shallow freshwater ecosystems. Therefore, to control internal sources and transformations of P, Plant Debris should be removed and harvested. This study also indicates that intervention is needed to ensure the health of freshwater ecosystems, and we cannot hope to get satisfactory results from only improving the national wastewater discharge standards.
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evidence for organic phosphorus activation and transformation at the sediment water interface during Plant Debris decomposition
Science of The Total Environment, 2017Co-Authors: Wenqiang Zhang, Xin Meng, Wenzhong Tang, Baoqing ShanAbstract:Abstract The processes and mechanisms through which phosphorus (P) is released from sediment and organic P is transformed, induced by the decomposition of Plant (duckweed ( Lemma minor L.)) Debris, were studied experimentally. In the simulation experiments, the dissolved oxygen concentration, pH, and oxidation–reduction potential at the water–sediment interface first decreased rapidly. The lowest oxidation–reduction potential reached was 225.4 mV, and the solution became weakly acidic (pH 5.14) and anoxic (dissolved oxygen concentration 0.17 mg·L − 1 ). The dissolved oxygen concentration, pH, and oxidation–reduction potential then became stable. The soluble reactive P, total dissolved P, and total P concentrations in the overlying water all increased rapidly because of the particulate P and dissolved organic P released as the Plant Debris decomposed. 31 P NMR analysis of the solution showed that orthophosphate monoesters were the main organic P compounds in the sediment. The orthophosphate monoester and orthophosphate diester concentrations were higher during the first 7 d of the experiment (at 71.2 and 15.3 mg·kg − 1 , respectively) than later (60.8 and 14.6 mg·kg − 1 , respectively). The decomposition of the duckweed could have mineralized the orthophosphate monoesters and orthophosphate diesters to give orthophosphate. The results indicated that the decomposition of aquatic Plant Debris is a key factor in the release of P from sediment even when external P is excluded. It is therefore necessary to remove Plant Debris from freshwater ecosystems to control the release of P from Plant Debris and sediment.
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Evidence for organic phosphorus activation and transformation at the sediment–water interface during Plant Debris decomposition
Science of The Total Environment, 2017Co-Authors: Wenqiang Zhang, Xin Meng, Wenzhong Tang, Baoqing ShanAbstract:Abstract The processes and mechanisms through which phosphorus (P) is released from sediment and organic P is transformed, induced by the decomposition of Plant (duckweed ( Lemma minor L.)) Debris, were studied experimentally. In the simulation experiments, the dissolved oxygen concentration, pH, and oxidation–reduction potential at the water–sediment interface first decreased rapidly. The lowest oxidation–reduction potential reached was 225.4 mV, and the solution became weakly acidic (pH 5.14) and anoxic (dissolved oxygen concentration 0.17 mg·L − 1 ). The dissolved oxygen concentration, pH, and oxidation–reduction potential then became stable. The soluble reactive P, total dissolved P, and total P concentrations in the overlying water all increased rapidly because of the particulate P and dissolved organic P released as the Plant Debris decomposed. 31 P NMR analysis of the solution showed that orthophosphate monoesters were the main organic P compounds in the sediment. The orthophosphate monoester and orthophosphate diester concentrations were higher during the first 7 d of the experiment (at 71.2 and 15.3 mg·kg − 1 , respectively) than later (60.8 and 14.6 mg·kg − 1 , respectively). The decomposition of the duckweed could have mineralized the orthophosphate monoesters and orthophosphate diesters to give orthophosphate. The results indicated that the decomposition of aquatic Plant Debris is a key factor in the release of P from sediment even when external P is excluded. It is therefore necessary to remove Plant Debris from freshwater ecosystems to control the release of P from Plant Debris and sediment.
Miguel De Caragarcia - One of the best experts on this subject based on the ideXlab platform.
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greenhouse soil biosolarization with tomato Plant Debris as a unique fertilizer for tomato crops
International Journal of Environmental Research and Public Health, 2019Co-Authors: Pablo Garciaraya, Cesar Ruizolmos, Jose Ignacio Maringuirao, Carlos Asensiogrima, J C Tellomarquina, Miguel De CaragarciaAbstract:Intensive greenhouse horticulture can cause various environmental problems. Among these, the management, storage, and processing of crop residues can provoke aquifer contamination, pest proliferation, bad odors, or the abuse of phytosanitary treatments. Biosolarization adds value to any fresh Plant residue and is an efficient technique for the control of soil-borne diseases. This study aims to examine an alternative means of managing greenhouse crop residues through biosolarization and to investigate the influence of organic matter on yield and quality of tomato (Solanum lycopersicum, L.) fruit. With this purpose, the following nutritional systems were evaluated: inorganic fertilization with and without brassica pellets (Fert, Fert +, and Fert ++), fresh tomato Plant Debris with and without brassica pellets (Rest, Rest +, and Rest ++), and no fertilizer application (Control). The addition of organic matter was equal across all the treatments except for the control with regard to yield and quality of the tomato fruit. In light of these results, the application of tomato Plant Debris to the soil through biosolarization is postulated as an alternative for the management of crop residues, solving an environmental problem and having a favorable impact on the production and quality of tomatoes as a commercial crop.
Michel Legrand - One of the best experts on this subject based on the ideXlab platform.
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concentration of atmospheric cellulose a proxy for Plant Debris across a west east transect over europe
Journal of Geophysical Research, 2007Co-Authors: Asuncion Sanchezochoa, Anne Kaspergiebl, H Puxbaum, Andras Gelencser, Michel LegrandAbstract:[1] Atmospheric “free cellulose” has been determined as a proxy for “Plant Debris” in samples from six background stations on a west-east transect extending from the Atlantic (Azores) to the mid-European background site KPZ (K-Puszta, Hungary). Concentration levels of cellulose (biannual averages) range from 16.3 ng/m3 at the oceanic background site AZO (Azores) to 181 ng/m3 at KPZ (Hungary). Concentrations decrease with elevation, winter levels at the midtropospheric Sonnblick site (SBO, 3106 m) are comparable to clean Atlantic conditions. The atmospheric concentration of Plant Debris (biannual averages) was derived from the cellulose data and ranges from 33.4 ng/m3 at AZO to 363 ng/m3 at KPZ. Relative contributions of Plant Debris to organic matter (OM) range from around 2% at the semirural coastal site Aveiro (AVE) to 10% at SBO. Surprisingly high relative concentrations of Plant Debris in OM were observed for wintry conditions at the elevated sites. The relative fraction of Plant Debris in OM ranged as averages from 6.1% at Schauinsland, Germany (1205 m) to 10.1% at Puy de Dome, France (1405 m) and 22.4% at Sonnblick, Austria (3106 m). Thus Plant Debris is a very important constituent of the organic material at elevated background sites with summer concentrations of around 5% and winter levels from around 6–22% depending on elevation. Since cellulose is considered rather long-lived with respect to atmospheric oxidation processes, it may become enriched on the way to background regions, which may explain the elevated relative levels at elevated sites.
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Concentration of atmospheric cellulose: A proxy for Plant Debris across a west-east transect over Europe
Journal of Geophysical Research, 2007Co-Authors: Asunción Sánchez-ochoa, H Puxbaum, Andras Gelencser, Anne Kasper-giebl, Michel LegrandAbstract:International audienceAtmospheric “free cellulose” has been determined as a proxy for “Plant Debris” in samples from six background stations on a west-east transect extending from the Atlantic (Azores) to the mid-European background site KPZ (K-Puszta, Hungary). Concentration levels of cellulose (biannual averages) range from 16.3 ng/m3 at the oceanic background site AZO (Azores) to 181 ng/m3 at KPZ (Hungary). Concentrations decrease with elevation, winter levels at the midtropospheric Sonnblick site (SBO, 3106 m) are comparable to clean Atlantic conditions. The atmospheric concentration of Plant Debris (biannual averages) was derived from the cellulose data and ranges from 33.4 ng/m3 at AZO to 363 ng/m3 at KPZ. Relative contributions of Plant Debris to organic matter (OM) range from around 2% at the semirural coastal site Aveiro (AVE) to 10% at SBO. Surprisingly high relative concentrations of Plant Debris in OM were observed for wintry conditions at the elevated sites. The relative fraction of Plant Debris in OM ranged as averages from 6.1% at Schauinsland, Germany (1205 m) to 10.1% at Puy de Dome, France (1405 m) and 22.4% at Sonnblick, Austria (3106 m). Thus Plant Debris is a very important constituent of the organic material at elevated background sites with summer concentrations of around 5% and winter levels from around 6–22% depending on elevation. Since cellulose is considered rather long-lived with respect to atmospheric oxidation processes, it may become enriched on the way to background regions, which may explain the elevated relative levels at elevated sites
Robert L. Gilbertson - One of the best experts on this subject based on the ideXlab platform.
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Role of Crop Debris and Weeds in the Epidemiology of Bacterial Leaf Spot of Lettuce in California
Plant Disease, 2001Co-Authors: Jeri D. Barak, Steven T. Koike, Robert L. GilbertsonAbstract:ABSTRACT Bacterial leaf spot of lettuce (BLS), caused by Xanthomonas campestris pv. vitians, has increased in importance in California over the past 5 years. The pathogen can be seedborne, but it was not recovered from selected commercial lettuce seed lots Planted during this time. Survival of X. campestris pv. vitians in association with Plant Debris was investigated in a 3-year field experiment in Salinas, CA. The initial lettuce spring crop was spray inoculated with X. campestris pv. vitians, which resulted in 100% disease incidence. Spring crops were followed by a 1-month summer fallow period, whereas fall crops were followed by a 5-month winter fallow period. High populations of X. campestris pv. vitians (up to 106 CFU/g) were recovered from lettuce Plant Debris after the 1-month summer fallow and BLS developed on all subsequent fall lettuce crops. During the winter fallow period, X. campestris pv. vitians populations associated with Plant Debris declined and, by 2 months after harvest, only small po...
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Role of Crop Debris and Weeds in the Epidemiology of Bacterial Leaf Spot of Lettuce in California
Plant Disease, 2001Co-Authors: Jeri D. Barak, Steven T. Koike, Robert L. GilbertsonAbstract:Bacterial leaf spot of lettuce (BLS), caused by Xanthomonas campestris pv. vitians, has in- creased in importance in California over the past 5 years. The pathogen can be seedborne, but it was not recovered from selected commercial lettuce seed lots Planted during this time. Survival of X. campestris pv. vitians in association with Plant Debris was investigated in a 3-year field experiment in Salinas, CA. The initial lettuce spring crop was spray inoculated with X. campes- tris pv. vitians, which resulted in 100% disease incidence. Spring crops were followed by a 1- month summer fallow period, whereas fall crops were followed by a 5-month winter fallow period. High populations of X. campestris pv. vitians (up to 106 CFU/g) were recovered from lettuce Plant Debris after the 1-month summer fallow and BLS developed on all subsequent fall lettuce crops. During the winter fallow period, X. campestris pv. vitians populations associated with Plant Debris declined and, by 2 months after harvest, only small populations were detected. Spring crops also developed BLS, but at reduced levels. X. campestris pv. vitians was recovered from leaves of several symptomless weed species collected around commercial infested fields, but not from weeds collected around previously infested fields during fallow periods. During the course of this study, an X. campestris pv. vitians-specific polymerase chain reaction primer pair was developed.
Wenqiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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phosphorus transformations at the sediment water interface in shallow freshwater ecosystems caused by decomposition of Plant Debris
Chemosphere, 2018Co-Authors: Wenqiang Zhang, Xin Meng, Wenzhong Tang, Baoqing ShanAbstract:Abstract We studied the processes and mechanisms that drove phosphorus (P) release and transformations at the sediment-water interface (SWI) because of the decomposition of Plant Debris. The results showed that, as the simulation time increased, the pH, dissolved oxygen (DO), and oxidation reduction potential (ORP) in Duckweed+Sediment+Water (DWS) and Duckweed+Water (DW) initially decreased and then increased before stabilizing. Changes in the physicochemical characteristics affect the microhabitat and the release and transformations of P at the SWI. The initial flux of total P (TP), total dissolved phosphorus (TDP), and soluble reactive phosphorus (SRP) was 886, 515, and 441 mg m−2 d−1 in DWS and 626, 376, and 330 mg m−2 d−1 in DW, respectively. As the Plant Debris decomposed, the fluxes of TP, TDP, and SRP decreased, and after 11 days, the fluxes remained at around 0 mg m−2 d−1. The dissolved organic phosphorus (DOP) flux followed different trends in DWS and DW, and increased first to a maximum of 285 and 109 mg m−2 d−1, respectively, by day 6. The results of this study indicate that Plant Debris decomposition drive P transformations at the SWI in shallow freshwater ecosystems. Therefore, to control internal sources and transformations of P, Plant Debris should be removed and harvested. This study also indicates that intervention is needed to ensure the health of freshwater ecosystems, and we cannot hope to get satisfactory results from only improving the national wastewater discharge standards.
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evidence for organic phosphorus activation and transformation at the sediment water interface during Plant Debris decomposition
Science of The Total Environment, 2017Co-Authors: Wenqiang Zhang, Xin Meng, Wenzhong Tang, Baoqing ShanAbstract:Abstract The processes and mechanisms through which phosphorus (P) is released from sediment and organic P is transformed, induced by the decomposition of Plant (duckweed ( Lemma minor L.)) Debris, were studied experimentally. In the simulation experiments, the dissolved oxygen concentration, pH, and oxidation–reduction potential at the water–sediment interface first decreased rapidly. The lowest oxidation–reduction potential reached was 225.4 mV, and the solution became weakly acidic (pH 5.14) and anoxic (dissolved oxygen concentration 0.17 mg·L − 1 ). The dissolved oxygen concentration, pH, and oxidation–reduction potential then became stable. The soluble reactive P, total dissolved P, and total P concentrations in the overlying water all increased rapidly because of the particulate P and dissolved organic P released as the Plant Debris decomposed. 31 P NMR analysis of the solution showed that orthophosphate monoesters were the main organic P compounds in the sediment. The orthophosphate monoester and orthophosphate diester concentrations were higher during the first 7 d of the experiment (at 71.2 and 15.3 mg·kg − 1 , respectively) than later (60.8 and 14.6 mg·kg − 1 , respectively). The decomposition of the duckweed could have mineralized the orthophosphate monoesters and orthophosphate diesters to give orthophosphate. The results indicated that the decomposition of aquatic Plant Debris is a key factor in the release of P from sediment even when external P is excluded. It is therefore necessary to remove Plant Debris from freshwater ecosystems to control the release of P from Plant Debris and sediment.
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Evidence for organic phosphorus activation and transformation at the sediment–water interface during Plant Debris decomposition
Science of The Total Environment, 2017Co-Authors: Wenqiang Zhang, Xin Meng, Wenzhong Tang, Baoqing ShanAbstract:Abstract The processes and mechanisms through which phosphorus (P) is released from sediment and organic P is transformed, induced by the decomposition of Plant (duckweed ( Lemma minor L.)) Debris, were studied experimentally. In the simulation experiments, the dissolved oxygen concentration, pH, and oxidation–reduction potential at the water–sediment interface first decreased rapidly. The lowest oxidation–reduction potential reached was 225.4 mV, and the solution became weakly acidic (pH 5.14) and anoxic (dissolved oxygen concentration 0.17 mg·L − 1 ). The dissolved oxygen concentration, pH, and oxidation–reduction potential then became stable. The soluble reactive P, total dissolved P, and total P concentrations in the overlying water all increased rapidly because of the particulate P and dissolved organic P released as the Plant Debris decomposed. 31 P NMR analysis of the solution showed that orthophosphate monoesters were the main organic P compounds in the sediment. The orthophosphate monoester and orthophosphate diester concentrations were higher during the first 7 d of the experiment (at 71.2 and 15.3 mg·kg − 1 , respectively) than later (60.8 and 14.6 mg·kg − 1 , respectively). The decomposition of the duckweed could have mineralized the orthophosphate monoesters and orthophosphate diesters to give orthophosphate. The results indicated that the decomposition of aquatic Plant Debris is a key factor in the release of P from sediment even when external P is excluded. It is therefore necessary to remove Plant Debris from freshwater ecosystems to control the release of P from Plant Debris and sediment.