{"title":"Effects of dissolved organic matter on mercury speciation in rice rhizosphere amended with sulfur-rich biochar","authors":"Hualing Hu , Yiman Gao , Wenbing Tan , Beidou Xi","doi":"10.1016/j.seh.2023.100022","DOIUrl":"https://doi.org/10.1016/j.seh.2023.100022","url":null,"abstract":"<div><p>Natural sulfur (S)-rich biochar (NRB) can be employed as an alternative for traditional S-modified biochar. However, the effect of dissolved organic matter (DOM) on mercury (Hg) speciation in rice rhizosphere soils under natural S-rich biochar application remains unclear. We conducted a pot experiment to study the effects of NRB application on the chemical composition and structure of DOM and the related speciation and availability of Hg in rice rhizosphere. Applying NRB significantly increased the concentration of methylmercury (MeHg) in the rhizosphere soils, which was enhanced with application frequency. This observation can be explained by MeHg immobilization in response to increasing S content in rice rhizosphere soils. We also observed increased molecular weight and functional group complexity of DOM, likely contributing to the decrease in MeHg mobility. Furthermore, the increase in pH and humification of DOM caused by S-rich biochar application generally reduced the concentrations of water-soluble and mercuric-sulfide fraction (easily-available Hg species) and organo-chelated fraction (potentially-available Hg species). Our findings highlight that the application of NRB can reduce the availability of MeHg in rice rhizosphere, thus providing a practical basis for reducing the potential risk of MeHg toxicity.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"1 2","pages":"Article 100022"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49858913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sean C. Stokes , Pankaj Trivedi , Kristen Otto , James A. Ippolito , Thomas Borch
{"title":"Determining soil health parameters controlling crop productivity in a Citrus Greening disease affected orange grove","authors":"Sean C. Stokes , Pankaj Trivedi , Kristen Otto , James A. Ippolito , Thomas Borch","doi":"10.1016/j.seh.2023.100016","DOIUrl":"https://doi.org/10.1016/j.seh.2023.100016","url":null,"abstract":"<div><p>Soil health is an important aspect for maintaining adequate crop production, but the specifics of what entails a healthy soil can vary from region to region and crop to crop. In highly managed agricultural systems, unhealthy soil can be masked by intensive management practices, yet there must be detrimental cutoff points in various characteristics, such as soil organic matter (SOM) concentrations, where even highly managed systems start to lose productivity. This negative impact was observed in a Florida citrus grove containing Valencia orange trees with observable differences in tree size yet were otherwise managed identically. A soil health index demonstrated that the areas with smaller trees had a significantly lower index score and those soils contained significantly less SOM (average SOM = 0.57%) compared to areas with larger trees (average SOM = 0.94%). The areas of lower crop productivity also had less enzymatic activity of common carbon-cycling enzymes and different microbial populations, which all together negatively affected soil health and corresponding plant productivity. This agricultural region is also known to have a Citrus Greening disease (HLB) infection rate of close to 100%, hence we developed a hypothesis that could explain how progression of this infection could be impacted by SOM concentrations and differences in microbial diversity. We posit that areas of this grove with healthier soil could have more resistance to the onset of fatal HLB symptoms. Consequently, soil organic matter distribution and concentration should be considered when establishing new groves in order to optimize soil and crop productivity.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"1 2","pages":"Article 100016"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49858910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weixin Fan , Chunsheng Qiu , Qian Qu , Xiangang Hu , Li Mu , Ziwei Gao , Xin Tang
{"title":"Sources and identification of microplastics in soils","authors":"Weixin Fan , Chunsheng Qiu , Qian Qu , Xiangang Hu , Li Mu , Ziwei Gao , Xin Tang","doi":"10.1016/j.seh.2023.100019","DOIUrl":"https://doi.org/10.1016/j.seh.2023.100019","url":null,"abstract":"<div><p>Large-scale production, rapid consumption, insufficient recovery and management, and slow degradation lead to a large accumulation of plastic waste and microplastics. Microplastics are characterized as stable, small, and having a large specific surface area and strong hydrophobicity. They are carriers of many hydrophobic organic pollutants, heavy metals, pathogenic bacteria and drug resistance genes. Worldwide, microplastic pollution in soils has attracted much attention. The progress and perspectives in the separation and detection of soil microplastics deserve a comprehensive review and discussion. Here, the sources and distributions of microplastics in soil from the use of agricultural plastic film, sludge recycling, long-term application of organic fertilizer, surface runoff, and sewage irrigation are summarized. Physical separation methods such as density separation, electrostatic separation, oil extraction and pressurized liquid extraction, and chemical extraction methods such as acid digestion, alkaline digestion, hydrogen peroxide and Fenton reagent oxidation, and enzymatic hydrolysis for soil microplastics are reviewed. Futhermore, the detection technologies of soil microplastics through microscopy, spectroscopy, mass spectrometry, thermogravimetric analysis, differential scanning calorimetry, X-ray photoelectron spectroscopy and nuclear magnetic resonance are reviewed. Finally, the perspectives are put forward from understanding the impacts of microplastics on soil functions and health, developing source control and environmental remediation technology, investigating low-cost and rapid separation and extraction methods that preserve the characteristics of microplastics, strengthen the degree of automation to avoid artificial operation error, and establish the standard methods for isolating, extracting, identifying, and quantifying microplastics in soils. This review serves as a technical reference for rapid identification of soil microplastics and builds the foundation for scientific assessment of the ecological and human environmental risks of soil microplastics.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"1 2","pages":"Article 100019"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49899670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Retention and loss pathways of soluble nutrients in biochar-treated slope land soil based on a rainfall simulator","authors":"Selly Maisyarah , Jyun-Yuan Chen , Zeng-Yei Hseu , Shih-Hao Jien","doi":"10.1016/j.seh.2023.100021","DOIUrl":"https://doi.org/10.1016/j.seh.2023.100021","url":null,"abstract":"<div><p>Global food crisis makes intense agricultural activity necessary, which accelerates soil degradation and increases pollution risk to nearby catchments. Application of biochar can effectively retain plant-required nutrients in soils. However, the linkage between retention and loss pathways of nutrients is still unclear, particularly at slope lands. Therefore, a simulated rainfall experiment (rainfall intensity = 50 mm h<sup>−1</sup>) was conducted in a sandy soil with 10° gradient slope (indoor experiment) to clarify loss pathways of soluble C, N, P and K in biochar-amended soils. Wood biochar pyrolized at 300 °C (LWB) or 600 °C (HWB) was applied at 1% (LWB1; HWB1) or 2% (LWB2; HWB2). Our results show that the pathways for C, N, P and K loss was percolation > surface runoff > soil erosion. Compared to control, HWB2 treatment had a 2–4 times higher infiltration amount but 5–6 times lower surface runoff and soil loss, indicating that this treatment alleviated nutrient loss via erosion and runoff in the sloped soil. Among all treatments, HWB2 treatment was the most effective for retaining organic C, dissolved organic C, total N, and exchangeable K through various pathways. However, a substantial amount of soluble P was lost through percolation. Therefore, the potential pollution of groundwater by P through percolation pathway should be considered during biochar application.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"1 2","pages":"Article 100021"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49899672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of limed manure digestate application in sandy soil on plant nitrogen availability and soil N2O emissions","authors":"Roy Posmanik , Ali Nejidat , Amit Gross","doi":"10.1016/j.seh.2023.100006","DOIUrl":"https://doi.org/10.1016/j.seh.2023.100006","url":null,"abstract":"<div><p>Anaerobically-digested manure is frequently applied to agricultural soil to enhance plant growth and reduce the need for chemical fertilizers. This practice also stimulates microbial nitrogen transformations and often results in N<sub>2</sub>O emissions. A single mesophilic anaerobic digestion is insufficient for pathogen removal or inactivation and therefore, a post treatment is required for its stabilization and hygienization. Here, we examined the effects of limed manure-digestate as a nitrogen source for plant growth and on N<sub>2</sub>O emission compared with compost. A plant growth experiment was conducted in a sandy soil and N<sub>2</sub>O emissions were monitored throughout the experiment. Plants were irrigated with freshwater or liquid-N fertilizer. The combination of compost application and liquid-N fertilizer resulted in surface N<sub>2</sub>O fluxes over 0.7 mg m<sup>−2</sup> d<sup>−1</sup>, which were correlated with ammonium concentration in the soil. The presence of N<sub>2</sub>O in the rhizosphere was only detected in compost-amended soil 2–10 days after plantation. A significantly-lower surface N<sub>2</sub>O flux of 0.4 mg m<sup>−2</sup> d<sup>−1</sup> was recorded with application of limed-digestate, probably due to its effects on nitrogen-transforming microorganisms. Both compost and limed-digestate enhanced plant growth, with a more distinct effect in the freshwater treatment. Our observations demonstrate that limed-digestate can be an efficient substitute for compost as it effectively supports plant growth with substantially-lower N<sub>2</sub>O emissions.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"1 1","pages":"Article 100006"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49880274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Occurrence of per- and polyfluoroalkyl substances (PFAS) in soil: Sources, fate, and remediation","authors":"Yifei Wang, Umar Munir, Qingguo Huang","doi":"10.1016/j.seh.2023.100004","DOIUrl":"https://doi.org/10.1016/j.seh.2023.100004","url":null,"abstract":"<div><p>Per- and polyfluoroalkyl substances (PFAS) are being widely investigated for their distribution and remediation in the environment. It is crucial to consider the interactions of PFAS between soil and the other media in the ecosystem, including air, water, and plants, when studying their fate and transport in soil, while few studies have taken such an integrative approach. This review examined the potential input of PFAS to soil from air, water, and landfill by analyzing both the PFAS concentration in each source and the mechanisms by which a soil is impacted by PFAS from these sources. It was found that PFAS in air (on average 10<sup>1−2</sup> pg/m<sup>3</sup>) and landfill leachates (on average 10<sup>0-</sup><sup>2</sup> ng/L) are the main sources of PFAS in soil. Many factors, such as solution pH and cations, influence sorption and desorption of PFAS in the water-soil interface, but no single factor is deterministic. The migration of PFAS from soil to plant through root uptake was found in many plant species, including wheat and maize, and the effects vary with different PFAS and plant species. PFAS levels in soil were associated with land-use type. They were the highest in the primary exposure sites (10<sup>−1</sup>-10<sup>2</sup> ng/g), followed by secondary exposure sites (10<sup>−1</sup>-10<sup>1</sup> ng/g), and background sites (10<sup>−2</sup>-10<sup>1</sup> ng/g), with legacy PFAS- PFOA (10<sup>0-</sup><sup>1</sup> ng/g) and PFOS (10<sup>0-</sup><sup>2</sup> ng/g) as the most predominant. There are a few promising destructive technologies targeted at PFAS in soil, such as thermal treatment and ultrasound, but still need to overcome low efficiency and high cost to scale up. In the meantime, PFAS may either be immobilized in soil or be removed for ex-situ treatment.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"1 1","pages":"Article 100004"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49880279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Evgenios Agathokleous , Chen-Jing Liu , Edward J. Calabrese
{"title":"Applications of the hormesis concept in soil and environmental health research","authors":"Evgenios Agathokleous , Chen-Jing Liu , Edward J. Calabrese","doi":"10.1016/j.seh.2023.100003","DOIUrl":"https://doi.org/10.1016/j.seh.2023.100003","url":null,"abstract":"<div><p>Hormesis refers to positive biological effects caused by exposure to low doses of a stressor known to be toxic at higher doses. These effects include an enhanced defense system and stimulated plant/microorganism growth and reproduction. Hormesis has emerged as a fundamental concept with broad relevance to the field of soil and environmental health. Its utilization in evaluating environmental effects and ecotoxicity can reduce uncertainties introduced by extrapolating from high to low doses of pollutants. Similarly, its consideration in risk assessment can help tackle toxicity risks imposed by chemical mixtures. Further, it can maximize the effectiveness of novel agrochemicals applied at the lowest possible concentration, thus reducing their ecological and human risks. Hormesis-based interventions, such as plant priming and stimulation of beneficial insects and waste-degrading microbes, can further reduce agrochemical loads into the environment, thereby enhancing plant and soil health. Inclusion of hormesis in strategies to control harmful organisms, such as pests, pathogenic microbes and harmful algal bloom organisms, can aid in combating chemical resistance. Hormesis-inclusive studies also provide useful information regarding suitable pollutant tolerance levels for microorganisms and plants during bioremediation and phytoremediation, thus enhancing environmental remediation. In sum, hormesis is highly relevant and offers numerous potential applications in soil and environmental health research.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"1 1","pages":"Article 100003"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49880275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xingdong Shi , Zhijie Chen , Wei Wei , Jun Chen , Bing-Jie Ni
{"title":"Toxicity of micro/nanoplastics in the environment: Roles of plastisphere and eco-corona","authors":"Xingdong Shi , Zhijie Chen , Wei Wei , Jun Chen , Bing-Jie Ni","doi":"10.1016/j.seh.2023.100002","DOIUrl":"https://doi.org/10.1016/j.seh.2023.100002","url":null,"abstract":"<div><p>Micro/nanoplastics (MPs/NPs) are a growing threat to environmental health as these particles are dispersed to remote locations. However, the migration process of NPs differs from MPs due to their differences in sizes and physicochemical properties, thereby inducing different environmental behaviours and fates. While MPs provide surfaces to host microorganisms to form a plastisphere, NPs are smaller than microorganisms, which are often encapsulated by protein or organic matter to form unique eco-corona. Both plastisphere and eco-corona alter the physiochemical property of MPs/NPs, thereby changing their environmental toxicity. To fully understand the toxicity of MPs/NPs after forming plastisphere or eco-corona, this review aims to evaluate the roles and toxicities of MPs/NPs in the environment. Specifically, this review discusses the formation of plastisphere on MPs and eco-corona on NPs, summarizes the biochemical mechanisms of toxicity of MPs/NPs, and assesses their potential health threats to humans. Finally, perspectives are provided to better manage plastic pollution to protect the environment and human health.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"1 1","pages":"Article 100002"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49880278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huan Chen , Alexander Martin Rücker , Yina Liu , David Miller , Jia-Ning Dai , Jun-Jian Wang , Dennis O. Suhre , Li-Jung Kuo , William H. Conner , Barbara J. Campbell , Robert C. Rhew , Alex T. Chow
{"title":"Unique biogeochemical characteristics in coastal ghost forests – The transition from freshwater forested wetland to salt marsh under the influences of sea level rise","authors":"Huan Chen , Alexander Martin Rücker , Yina Liu , David Miller , Jia-Ning Dai , Jun-Jian Wang , Dennis O. Suhre , Li-Jung Kuo , William H. Conner , Barbara J. Campbell , Robert C. Rhew , Alex T. Chow","doi":"10.1016/j.seh.2023.100005","DOIUrl":"https://doi.org/10.1016/j.seh.2023.100005","url":null,"abstract":"<div><p>Seawater intrusion by rising sea levels has created large areas of ghost forests along low-lying coastal wetlands in the southeastern USA, but more information is needed to better understand its soil biogeochemistry. Here, we characterized several soil and environmental parameters, including tree litterfall, surface and soil porewater quality, emissions of greenhouse gases, and microbial communities along a forest-to-marsh transect, including a freshwater forested wetland, a salt-impacted degraded ghost forest, and a salt marsh in Winyah Bay, SC, USA. General water quality parameters such as electrical conductivity, dissolved oxygen, temperature and aboveground productivity showed distinct trends along the freshwater forested wetland → degraded ghost forest → salt marsh transect, whereas there were no obvious trends in soil biogeochemical parameters. Concentrations of dissolved organic carbon (DOC) in the degraded ghost forest were generally similar to the freshwater forested wetland, but on average were higher than those in the salt marsh. More labile molecular features observed through Fourier transform ion cyclotron resonance mass spectrometry indicated an increase in the DOC biodegradability along the forest-to-marsh transect. Greater DOC biodegradability in the degraded ghost forest was observed and confirmed through its generation of the highest average electrical currents from sediment microbial fuel cells. The lowest CH<sub>4</sub> and CO<sub>2</sub> fluxes, but the highest degradable DOC, were observed in the degraded ghost forest, suggesting that lateral C export is important in this wetland. Moreover, the degraded ghost forest was dominated by a unique microbial community, including high abundance of Woesearchaeia, which enables carbon metabolism via symbiotic and/or fermentation-based lifestyles. Our study illustrates a ghost forest with very different characteristics compared to its parental freshwater forested wetland and its transitioned salt marsh. Data obtained from the two endmember ecosystems along the salinity gradient transect were not useful in predicting the unique biogeochemical processes in the degraded ghost forest.</p></div>","PeriodicalId":94356,"journal":{"name":"Soil & Environmental Health","volume":"1 1","pages":"Article 100005"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49880276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}