The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jianteng Sun - One of the best experts on this subject based on the ideXlab platform.
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organic contamination and remediation in the Agricultural Soils of china a critical review
Science of The Total Environment, 2018Co-Authors: Yu Zhan, Daniel C W Tsang, Jianteng Sun, Lili Pan, Lizhong ZhuAbstract:Abstract Soil pollution is a global problem in both developed and developing countries. Countries with rapidly developing economies such as China are faced with significant soil pollution problems due to accelerated industrialization and urbanization over the last decades. This paper provides an overview of published scientific data on soil pollution across China with particular focus on organic contamination in Agricultural Soils. Based on the related peer-reviewed papers published since 2000 (n = 203), we evaluated the priority organic contaminants across China, revealed their spatial and temporal distributions at the national scale, identified their possible sources and fates in soil, assessed their potential environmental risks, and presented the challenges in current remediation technologies regarding the combined organic pollution of Agricultural Soils. The primary pollutants in Northeast China were polycyclic aromatic hydrocarbons (PAHs) due to intensive fossil fuel combustion. The concentrations of organochlorine pesticides (OCPs) and phthalic acid esters (PAEs) were higher in North and Central China owing to concentrated Agricultural activities. The levels of polychlorinated biphenyls (PCBs) were higher in East and South China primarily because of past industrial operations and improper electronic waste processing. The co-existence of organic contaminants was severe in the Yangtze River Delta, Pearl River Delta, and Beijing-Tianjin-Hebei Region, which are the most populated and industrialized regions in China. Integrated biological-chemical remediation technologies, such as surfactant-enhanced bioremediation, have potential uses in the remediation of soil contaminated by multiple contaminants. This critical review highlighted several future research directions including combined pollution, interfacial interactions, food safety, bioavailability, ecological effects, and integrated remediation methods for combined organic pollution in soil.
Denis A Angers - One of the best experts on this subject based on the ideXlab platform.
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global nitrous oxide emission factors from Agricultural Soils after addition of organic amendments a meta analysis
Agriculture Ecosystems & Environment, 2017Co-Authors: Anais Charles, Denis A Angers, Joann K. Whalen, Martin H Chantigny, Philippe Rochette, Normand BertrandAbstract:Abstract Agricultural Soils receiving synthetic fertilizers and organic amendments containing nitrogen contribute a large part to anthropogenic nitrous oxide (N2O) emissions. As a source of nitrate that undergoes reduction to N2O, organic amendments also change soil C availability and redox potential, which influences the N2O emission factor (EF) of organically-amended Soils. The objective of this study was to conduct a meta-analysis of N2O EF from Agricultural Soils receiving organic amendments. A global survey of peer-reviewed literature resulted in the selection of 38 studies including 422 observations at 43 sites in 12 countries. The analysis yielded a global EF for all organic sources, EForg, equal to 0.57 ± 0.30%, which is lower than the IPCC default EF of 1 for synthetic fertilizers. Three groups of organic amendments with similar EFs were identified: the high-risk group including animal slurries, waste waters and biosolids (1.21 ± 0.14%); the medium-risk group including solid manure, composts + fertilizers, and crop residues + fertilizers (0.35 ± 0.13%); and the low-risk group including composts, crop residues, paper mill sludge and pellets (0.02 ± 0.13%). The EF was higher when Soils received organic amendments in combination with synthetic fertilizers, such as liquid manures + fertilizers (2.14 ± 0.53%), composts + fertilizers (0.37 ± 0.24%), and crop residues + fertilizers (0.59 ± 0.27%). The EF was modulated by amendment (C/N ratio), soil (texture, drainage, organic C and N) and climatic (precipitation) factors. For example, EFs were on average 2.8 times greater in fine-textured than coarse-textured Soils. We recommend site-specific EFs that consider organic amendment chemistry, soil characteristics, climate conditions and whether the organic amendment is applied alone or in combination with synthetic fertilizers.
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nitrogen transformations in cold and frozen Agricultural Soils following organic amendments
Soil Biology & Biochemistry, 2009Co-Authors: Karen Clark, Denis A Angers, Martin H Chantigny, Philippe Rochette, Leonetienne ParentAbstract:Abstract Though microbial activity is known to occur in frozen Soils, little is known about the fate of animal manure N applied in the fall to Agricultural Soils located in areas with prolonged winter periods. Our objective was to examine transformations of soil and pig slurry N at low temperatures. Loamy and clay Soils were either unamended (Control), amended with 15 NH 4 -labeled pig slurry, or amended with the pig slurry and wheat straw. Soils were incubated at −6, −2, 2, 6, and 10 °C. The amounts of NH 4 , NO 3 and microbial biomass N (MBN), and the presence of 15 N in these pools were monitored. Total mineral N, NO 3 and 15 NO 3 increased at temperature down to −2 °C in the loam soil and −6 °C in the clay soil, indicating that nitrification and mineralization proceeded in frozen Soils. Nitrification and mineralization rates were 1.8–4.9 times higher in the clay than in the loamy soil, especially below freezing point (3.2–4.9), possibly because more unfrozen water remained in the clay than in the loamy soil. Slurry addition increased nitrification rates by 3–14 times at all temperatures, indicating that this process was N-limited even in frozen Soils. Straw incorporation caused significant net N immobilization only at temperatures ≥2 °C in both Soils; the rates were 1.4–3.4 higher in the loam than in the clay soil. Nevertheless, up to 30% of the applied 15 N was present in MBN at all temperatures. These findings indicate that microbial N immobilization occurred in frozen Soils, but was not strong enough to induce net immobilization below the freezing point, even in the presence of straw. The Q 10 values for estimated mineralization and nitrification rates were one to two orders-of-magnitude larger below 2 °C than above this temperature (13–208 versus 1.5–6.9, respectively), indicating that these processes are highly sensitive to a small increase in soil temperature around the freezing point of water. This study confirms that net mineralization and nitrification can occur at potentially significant rates in frozen Agricultural Soils, especially in the presence of organic amendments. In contrast, net N immobilization could be detected essentially above the freezing point. Our results imply that fall-applied N could be at risk of overwinter losses, particularly in fine-textured Soils.
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greenhouse gas contributions of Agricultural Soils and potential mitigation practices in eastern canada
Soil & Tillage Research, 2005Co-Authors: E G Gregorich, P Rochette, A J Vandenbygaart, Denis A AngersAbstract:Abstract Agricultural Soils can constitute either a net source or sink of the three principal greenhouse gases, carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). We compiled the most up-to-date information available on the contribution of Agricultural Soils to atmospheric levels of these gases and evaluated the mitigation potential of various management practices in eastern Canada and northeastern USA. Conversion of native ecosystems to arable cropping resulted in a loss of ∼22% of the original soil organic carbon (C)—a release of about 123 Tg C to the atmosphere; drainage and cultivation of organic Soils resulted in an additional release of about 15 Tg C. Management practices that enhance C storage in soil include fertilization and legume- and forage-based rotations. Adopting no-till did not always increase soil C. This apparent absence of no-till effects on C storage was attributed to the type and depth of tillage, soil climatic conditions, the quantity and quality of residue C inputs, and soil fauna. Emission of N2O from soil increased linearly with the amount of mineral nitrogen (N) fertilizer applied (0.0119 kg N2O-N kg N−1). Application of solid manure resulted in substantially lower N2O emission (0.99 kg N2O-N ha−1 year−1) than application of liquid manure (2.83 kg N2O-N ha−1 year−1) or mineral fertilizer (2.82 kg N2O-N ha−1 year−1). Systems containing legumes produced lower annual N2O emission than fertilized annual crops, suggesting that alfalfa (Medicago sativa L.) and other legume forage crops be considered different from other crops when deriving national inventories of greenhouse gases from Agricultural systems. Plowing manure or crop stubble into the soil in the autumn led to higher levels of N2O production (2.41 kg N2O-N ha−1 year−1) than if residues were left on the soil surface (1.19 kg N2O-N ha−1 year−1). Elevated N2O emission during freeze/thaw periods in winter and spring, suggests that annual N2O emission based only on growing-season measurements would be underestimated. Although measurements of CH4 fluxes are scant, it appears that Agricultural Soils in eastern Canada are a weak sink of CH4, and that this sink may be diminished through manuring. Although the influence of Agricultural management on soil C storage and emission of greenhouse gases is significant, management practices often appear to involve offsets or tradeoffs, e.g., a particular practice may increase soil C storage but also increase emission of N2O. In addition, because of high variability, adequate spatial and temporal sampling are needed for accurate estimates of greenhouse gas flux and soil C stock. Therefore a full accounting of greenhouse gas contributions of Agricultural Soils is imperative for determining the true mitigation potential of management practices.
Lizhong Zhu - One of the best experts on this subject based on the ideXlab platform.
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organic contamination and remediation in the Agricultural Soils of china a critical review
Science of The Total Environment, 2018Co-Authors: Yu Zhan, Daniel C W Tsang, Jianteng Sun, Lili Pan, Lizhong ZhuAbstract:Abstract Soil pollution is a global problem in both developed and developing countries. Countries with rapidly developing economies such as China are faced with significant soil pollution problems due to accelerated industrialization and urbanization over the last decades. This paper provides an overview of published scientific data on soil pollution across China with particular focus on organic contamination in Agricultural Soils. Based on the related peer-reviewed papers published since 2000 (n = 203), we evaluated the priority organic contaminants across China, revealed their spatial and temporal distributions at the national scale, identified their possible sources and fates in soil, assessed their potential environmental risks, and presented the challenges in current remediation technologies regarding the combined organic pollution of Agricultural Soils. The primary pollutants in Northeast China were polycyclic aromatic hydrocarbons (PAHs) due to intensive fossil fuel combustion. The concentrations of organochlorine pesticides (OCPs) and phthalic acid esters (PAEs) were higher in North and Central China owing to concentrated Agricultural activities. The levels of polychlorinated biphenyls (PCBs) were higher in East and South China primarily because of past industrial operations and improper electronic waste processing. The co-existence of organic contaminants was severe in the Yangtze River Delta, Pearl River Delta, and Beijing-Tianjin-Hebei Region, which are the most populated and industrialized regions in China. Integrated biological-chemical remediation technologies, such as surfactant-enhanced bioremediation, have potential uses in the remediation of soil contaminated by multiple contaminants. This critical review highlighted several future research directions including combined pollution, interfacial interactions, food safety, bioavailability, ecological effects, and integrated remediation methods for combined organic pollution in soil.
Zunxiang Zeng - One of the best experts on this subject based on the ideXlab platform.
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phthalate esters paes emerging organic contaminants in Agricultural Soils in peri urban areas around guangzhou china
Environmental Pollution, 2008Co-Authors: Feng Zeng, Kunyan Cui, Zhiyong Xie, Min Liu, Guoquan Sun, Yujun Lin, Danling Luo, Zunxiang ZengAbstract:This study reports the first data on the concentrations and distribution of phthalate esters (PAEs) in the Agricultural Soils from the peri-urban areas of Guangzhou city. Sigma(16)PAEs concentrations ranged from 0.195 to 33.6 microg g(-1)-dry weight (dw). Elevated levels of PAEs were recorded in the vegetable fields located next to the urban districts, and a decreasing trend exists following the distance away from the urban center. Diisobutyl phthalate (DiBP), Di-n-butyl phthalate (DnBP), and Di(2-ethylhexyl) phthalate (DEHP) dominated the PAEs in the Agricultural Soils. Significant relationship (correlation coefficient R(2)=0.85, p<0.01, n=40) was present between the accumulation of PAEs and total organic carbons in Agricultural Soils. In addition, both pH and texture of Soils are found to be important factors affecting the level of PAEs. This study shows that the Agricultural Soils in the peri-urban area of Guangzhou city were moderately polluted by PAEs.
Yu Zhan - One of the best experts on this subject based on the ideXlab platform.
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organic contamination and remediation in the Agricultural Soils of china a critical review
Science of The Total Environment, 2018Co-Authors: Yu Zhan, Daniel C W Tsang, Jianteng Sun, Lili Pan, Lizhong ZhuAbstract:Abstract Soil pollution is a global problem in both developed and developing countries. Countries with rapidly developing economies such as China are faced with significant soil pollution problems due to accelerated industrialization and urbanization over the last decades. This paper provides an overview of published scientific data on soil pollution across China with particular focus on organic contamination in Agricultural Soils. Based on the related peer-reviewed papers published since 2000 (n = 203), we evaluated the priority organic contaminants across China, revealed their spatial and temporal distributions at the national scale, identified their possible sources and fates in soil, assessed their potential environmental risks, and presented the challenges in current remediation technologies regarding the combined organic pollution of Agricultural Soils. The primary pollutants in Northeast China were polycyclic aromatic hydrocarbons (PAHs) due to intensive fossil fuel combustion. The concentrations of organochlorine pesticides (OCPs) and phthalic acid esters (PAEs) were higher in North and Central China owing to concentrated Agricultural activities. The levels of polychlorinated biphenyls (PCBs) were higher in East and South China primarily because of past industrial operations and improper electronic waste processing. The co-existence of organic contaminants was severe in the Yangtze River Delta, Pearl River Delta, and Beijing-Tianjin-Hebei Region, which are the most populated and industrialized regions in China. Integrated biological-chemical remediation technologies, such as surfactant-enhanced bioremediation, have potential uses in the remediation of soil contaminated by multiple contaminants. This critical review highlighted several future research directions including combined pollution, interfacial interactions, food safety, bioavailability, ecological effects, and integrated remediation methods for combined organic pollution in soil.
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organophosphate pesticide in Agricultural Soils from the yangtze river delta of china concentration distribution and risk assessment
Environmental Science and Pollution Research, 2018Co-Authors: Zhiheng Li, Yu Zhan, Shen XuAbstract:Organophosphorus pesticides (OPPs) are used worldwide and pose great risks to human health. However, information on their presence in Agricultural Soils at regional scale and the associated risks is limited. In this study, an extensive investigation on Agricultural Soils was conducted throughout the Yangtze River Delta (YRD) of China to reveal the status of OPP pollution. The total concentrations of the nine OPPs ranged from <3.0 to 521 ng g−1 dry weight, with a mean of 64.7 ng g−1 dry weight and a detection rate of 93 %. Dimethoate was found to be the primary compound, followed by methyl parathion and parathion. The highest concentrations of OPPs were found in Jiangsu province due to the intensive Agricultural activities. The pollution of OPPs is also highly associated with the land use types. The lower concentrations of OPPs found in vegetable fields could be attributed to their easy photodegradation and hydrolysis in aerobic Soils. There was no significant difference in microbial communities among the sample sites, indicating that OPPs in Agricultural Soils of the YRD region cause negligible effects on microbiota. The risks of OPPs in the Soils to human health were further evaluated. The hazard indexes in all the soil samples were below 1, suggesting absence of non-cancer risks. This study provides valuable information for a better understanding of the pollution status of OPPs in Agricultural Soils and a scientific basis for soil quality assessments.
