Plant growth‐promoting rhizobacteria and other soil bacteria have the potential to improve soil hydro‐physical properties and processes through the production of extracellular polymeric substances (EPS). However, the mechanisms by which EPS mediates changes in soil properties and processes remain incompletely understood, partly due to variations in EPS composition produced under different environmental conditions. In this study, we investigated the influence of different bacterial traits on intrinsic soil properties and processes of evaporation and infiltration using sand treated with the wild‐type Bacillus subtilis variant (UD1022) and its two mutant variants, eps−$eps^{-}$ – tasA−$tasA^{-}$ and srf AC−$AC^{-}$ . The eps−$eps^{-}$ – tasA−$tasA^{-}$ mutant suppresses EPS production through alterations in the eps and tasA genes, while the srf AC−$AC^{-}$ mutant lacks the gene for surfactin production. Experimental results confirmed that the solution viscosity of the eps−$eps^{-}$ – tasA−$tasA^{-}$ mutant was the lowest and the solution surface tension of the srf AC−$AC^{-}$ mutant was the highest among the three tested bacteria strains. The distinct intrinsic properties of EPS produced by these bacterial strains resulted in varied hydro‐physical responses in the treated sand. Key influences included modifications in wettability, hydraulic decoupling (or mixed wettability), and aggregation, which collectively led to reduced evaporation rates and heterogeneous water distribution during infiltration in the bacteria‐treated sands. Our findings advance the understanding of the role bacterial EPS play in vadose zone hydrology and offer insights for the development of sustainable strategies for increasing water retention, supporting crop production in arid regions, and facilitating land restoration.
{"title":"Plant growth‐promoting rhizobacteria mediate soil hydro‐physical properties: An investigation with Bacillus subtilis and its mutants","authors":"Fatema Kaniz, Wenjuan Zheng, H. Bais, Yan Jin","doi":"10.1002/vzj2.20274","DOIUrl":"https://doi.org/10.1002/vzj2.20274","url":null,"abstract":"Plant growth‐promoting rhizobacteria and other soil bacteria have the potential to improve soil hydro‐physical properties and processes through the production of extracellular polymeric substances (EPS). However, the mechanisms by which EPS mediates changes in soil properties and processes remain incompletely understood, partly due to variations in EPS composition produced under different environmental conditions. In this study, we investigated the influence of different bacterial traits on intrinsic soil properties and processes of evaporation and infiltration using sand treated with the wild‐type Bacillus subtilis variant (UD1022) and its two mutant variants, eps−$eps^{-}$ – tasA−$tasA^{-}$ and srf AC−$AC^{-}$ . The eps−$eps^{-}$ – tasA−$tasA^{-}$ mutant suppresses EPS production through alterations in the eps and tasA genes, while the srf AC−$AC^{-}$ mutant lacks the gene for surfactin production. Experimental results confirmed that the solution viscosity of the eps−$eps^{-}$ – tasA−$tasA^{-}$ mutant was the lowest and the solution surface tension of the srf AC−$AC^{-}$ mutant was the highest among the three tested bacteria strains. The distinct intrinsic properties of EPS produced by these bacterial strains resulted in varied hydro‐physical responses in the treated sand. Key influences included modifications in wettability, hydraulic decoupling (or mixed wettability), and aggregation, which collectively led to reduced evaporation rates and heterogeneous water distribution during infiltration in the bacteria‐treated sands. Our findings advance the understanding of the role bacterial EPS play in vadose zone hydrology and offer insights for the development of sustainable strategies for increasing water retention, supporting crop production in arid regions, and facilitating land restoration.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46009903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anne Imig, Lea Augustin, J. Groh, T. Pütz, Tiantian Zhou, F. Einsiedl, A. Rein
Understanding transport and fate processes in the subsurface is of fundamental importance to identify the leaching potentials of herbicides or other compounds to groundwater resources. HYDRUS‐1D was used to simulate water flow and solute transport in arable land lysimeters. Simulations were compared to observed drainage rates and stable water isotopes (δ18O) in the drainage. Four different model setups were investigated and statistically evaluated for their model performance to identify dominant processes for water flow characterization in the vadose zone under similar cultivation management and climatic conditions. The studied lysimeters contain soil cores dominated by sandy gravel (Ly1) and clayey sandy silt (Ly2), both cropped with maize located in Wielenbach, Germany. First, a single‐porosity setup was chosen. For Ly1, modeling results were satisfactory, but for Ly2, the damping observed in the isotope signature of the drainage could not be fully covered. By considering immobile water with a dual‐porosity setup for Ly2, model performance improved. This could be due to a higher fraction of fine pores in Ly2 available for water storage, leading to mixing processes of isotopically enriched summer precipitation and lighter winter water. Accounting for isotopic evaporation fractionation processes in both model setups did not lead to improved model performance. Consequentially, the difference in soil hydraulic properties between the two lysimeters seems to impact water flow processes. Knowledge of such differences is crucial to prevent contamination and mitigate potential risks to soil and groundwater.
{"title":"Fate of herbicides in cropped lysimeters: 1. Influence of different processes and model structure on vadose zone flow","authors":"Anne Imig, Lea Augustin, J. Groh, T. Pütz, Tiantian Zhou, F. Einsiedl, A. Rein","doi":"10.1002/vzj2.20265","DOIUrl":"https://doi.org/10.1002/vzj2.20265","url":null,"abstract":"Understanding transport and fate processes in the subsurface is of fundamental importance to identify the leaching potentials of herbicides or other compounds to groundwater resources. HYDRUS‐1D was used to simulate water flow and solute transport in arable land lysimeters. Simulations were compared to observed drainage rates and stable water isotopes (δ18O) in the drainage. Four different model setups were investigated and statistically evaluated for their model performance to identify dominant processes for water flow characterization in the vadose zone under similar cultivation management and climatic conditions. The studied lysimeters contain soil cores dominated by sandy gravel (Ly1) and clayey sandy silt (Ly2), both cropped with maize located in Wielenbach, Germany. First, a single‐porosity setup was chosen. For Ly1, modeling results were satisfactory, but for Ly2, the damping observed in the isotope signature of the drainage could not be fully covered. By considering immobile water with a dual‐porosity setup for Ly2, model performance improved. This could be due to a higher fraction of fine pores in Ly2 available for water storage, leading to mixing processes of isotopically enriched summer precipitation and lighter winter water. Accounting for isotopic evaporation fractionation processes in both model setups did not lead to improved model performance. Consequentially, the difference in soil hydraulic properties between the two lysimeters seems to impact water flow processes. Knowledge of such differences is crucial to prevent contamination and mitigate potential risks to soil and groundwater.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43289625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leonardo Inforsato, S. Iden, W. Durner, A. Peters, Q. de Jong van Lier
Numerical modeling of soil water dynamics and storage is generally based on the Richards equation. Its solution requires knowledge of the soil hydraulic properties (SHP): the soil water retention function and the hydraulic conductivity function. To determine SHP, laboratory evaporation experiments are particularly popular because they provide data for both SHP functions. The evaluation by the simplified evaporation method (SEM) method, originally proposed by Schindler and subsequently improved by several authors, relies on linearization assumptions that allow for a relatively simple calculation scheme but result in biased conductivity data for some soils. The objective of this study is to propose and test an improved computational scheme for the hydraulic conductivity function. We present the new theory and show that it leads generally to higher accuracy of the conductivity function. The improvement is most pronounced for sandy soils and soil water pressure heads below −100 cm, where the original method provided data with bias.
{"title":"Improved calculation of soil hydraulic conductivity with the simplified evaporation method","authors":"Leonardo Inforsato, S. Iden, W. Durner, A. Peters, Q. de Jong van Lier","doi":"10.1002/vzj2.20267","DOIUrl":"https://doi.org/10.1002/vzj2.20267","url":null,"abstract":"Numerical modeling of soil water dynamics and storage is generally based on the Richards equation. Its solution requires knowledge of the soil hydraulic properties (SHP): the soil water retention function and the hydraulic conductivity function. To determine SHP, laboratory evaporation experiments are particularly popular because they provide data for both SHP functions. The evaluation by the simplified evaporation method (SEM) method, originally proposed by Schindler and subsequently improved by several authors, relies on linearization assumptions that allow for a relatively simple calculation scheme but result in biased conductivity data for some soils. The objective of this study is to propose and test an improved computational scheme for the hydraulic conductivity function. We present the new theory and show that it leads generally to higher accuracy of the conductivity function. The improvement is most pronounced for sandy soils and soil water pressure heads below −100 cm, where the original method provided data with bias.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44087763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peat and other organic soils (e.g., organo‐mineral soils) show distinctive volume changes through desiccation and wetting. Important processes behind volume changes are shrinkage and swelling. There is a long history of studies on shrinkage which were conducted under different schemes for soil descriptions, nomenclatures and parameters, measurement approaches, and terminologies. To date, these studies have not been harmonized in order to compare or predict shrinkage from different soil properties, for example, bulk density or substrate composition. This, however, is necessary to prevent biases in the determination of volume‐based soil properties or for the interpretation of elevation measurements in peatlands, in order to predict carbon dioxide emissions or uptake caused by microbial decomposition or peat formation. This study gives a comprehensive overview of shrinkage studies carried out in the last 100 years. Terminology and approaches are systematically classified. In part I, the concepts for shrinkage characteristics, measurement methods, and model approaches are summarized. Part II is a meta‐analysis of shrinkage studies on peat and other organic soils amended by own measurement data obtained by a three‐dimensional structured light scanner. The results show that maximum shrinkage has a wide range from 11% to 93% and is strongly affected by common soil properties (botanical composition, degree of decomposition, soil organic carbon, and bulk density). Showing a stronger correlation, bulk density was a better predictor than soil organic carbon, but maximum shrinkage showed a large spread over all types of peat and other organic soils and ranges of bulk density and soil organic carbon.
{"title":"Reviewing and analyzing shrinkage of peat and other organic soils in relation to selected soil properties","authors":"Ronny Seidel, U. Dettmann, B. Tiemeyer","doi":"10.1002/vzj2.20264","DOIUrl":"https://doi.org/10.1002/vzj2.20264","url":null,"abstract":"Peat and other organic soils (e.g., organo‐mineral soils) show distinctive volume changes through desiccation and wetting. Important processes behind volume changes are shrinkage and swelling. There is a long history of studies on shrinkage which were conducted under different schemes for soil descriptions, nomenclatures and parameters, measurement approaches, and terminologies. To date, these studies have not been harmonized in order to compare or predict shrinkage from different soil properties, for example, bulk density or substrate composition. This, however, is necessary to prevent biases in the determination of volume‐based soil properties or for the interpretation of elevation measurements in peatlands, in order to predict carbon dioxide emissions or uptake caused by microbial decomposition or peat formation. This study gives a comprehensive overview of shrinkage studies carried out in the last 100 years. Terminology and approaches are systematically classified. In part I, the concepts for shrinkage characteristics, measurement methods, and model approaches are summarized. Part II is a meta‐analysis of shrinkage studies on peat and other organic soils amended by own measurement data obtained by a three‐dimensional structured light scanner. The results show that maximum shrinkage has a wide range from 11% to 93% and is strongly affected by common soil properties (botanical composition, degree of decomposition, soil organic carbon, and bulk density). Showing a stronger correlation, bulk density was a better predictor than soil organic carbon, but maximum shrinkage showed a large spread over all types of peat and other organic soils and ranges of bulk density and soil organic carbon.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49599265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Application of biochar amendments in agricultural systems has received much attention in recent years. In this study, we assess the 5‐year impacts of biochar application on soil water and plant interactions for an irrigated fresh market tomato (Solanum lycopersicum) and a rainfed pasture (Poaceae) cropping system. In particular, we focus on three varieties of locally produced biochar from agricultural waste materials—almond shell, walnut shell, and almond pruning residues that are pyrolyzed using a mobile pyrolysis unit. We used the soil hydrological model HYDRUS‐1D to explicitly track seasonal and annual soil water fluxes through changes in water retention, drainage, evaporation, and plant water uptake under biochar application. Modeling results show that the application of biochar at 5% increased soil water availability within the top 20 cm for a rainfed system, irrespective of biochar amendment type. This is clearly indicative of higher plant water uptake and greater water use efficiency (WUE) under biochar application. In contrast, a similar biochar amendment for the irrigated system did not affect WUE, instead reducing seasonal soil evaporation loss and thereby reducing irrigation demand. In both cropping systems, year‐to‐year variability in precipitation significantly impacted the total amount of water saved under biochar application with certain amendments retaining more water than others. Given that biochar application increased water retention irrespective of cropping systems, we further used a simple approach to determine yield trade‐off, if any, between control and biochar treatments. Our economic balance clearly demonstrates that the water saved by amending soil with biochar does not offset the yield disparity if compensated with carbon credits and therefore, application of biochar should be actively considered for both its direct and indirect benefits to potential greenhouse gas mitigation (e.g., diverting orchard waste from open burning), water savings, and soil health.
{"title":"Impact of biochar amendments on soil water and plant uptake dynamics under different cropping systems","authors":"Touyee Thao, B. Arora, T. Ghezzehei","doi":"10.1002/vzj2.20266","DOIUrl":"https://doi.org/10.1002/vzj2.20266","url":null,"abstract":"Application of biochar amendments in agricultural systems has received much attention in recent years. In this study, we assess the 5‐year impacts of biochar application on soil water and plant interactions for an irrigated fresh market tomato (Solanum lycopersicum) and a rainfed pasture (Poaceae) cropping system. In particular, we focus on three varieties of locally produced biochar from agricultural waste materials—almond shell, walnut shell, and almond pruning residues that are pyrolyzed using a mobile pyrolysis unit. We used the soil hydrological model HYDRUS‐1D to explicitly track seasonal and annual soil water fluxes through changes in water retention, drainage, evaporation, and plant water uptake under biochar application. Modeling results show that the application of biochar at 5% increased soil water availability within the top 20 cm for a rainfed system, irrespective of biochar amendment type. This is clearly indicative of higher plant water uptake and greater water use efficiency (WUE) under biochar application. In contrast, a similar biochar amendment for the irrigated system did not affect WUE, instead reducing seasonal soil evaporation loss and thereby reducing irrigation demand. In both cropping systems, year‐to‐year variability in precipitation significantly impacted the total amount of water saved under biochar application with certain amendments retaining more water than others. Given that biochar application increased water retention irrespective of cropping systems, we further used a simple approach to determine yield trade‐off, if any, between control and biochar treatments. Our economic balance clearly demonstrates that the water saved by amending soil with biochar does not offset the yield disparity if compensated with carbon credits and therefore, application of biochar should be actively considered for both its direct and indirect benefits to potential greenhouse gas mitigation (e.g., diverting orchard waste from open burning), water savings, and soil health.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44566886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The role of hydropedology when aiming for the United Nations Sustainable Development Goals","authors":"J. Bouma","doi":"10.1002/vzj2.20269","DOIUrl":"https://doi.org/10.1002/vzj2.20269","url":null,"abstract":"","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43238502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
On the cover: A 3D data visualization of the elevation in the Schöfertal catchment (Germany). The digital elevation data are the primary source of information to quantify the data-related uncertainty of spatial soil moisture patterns estimated using an unsupervised multiple regression approach. See Paasche et al., “Quantification of data-related uncertainty of spatially dense soil moisture patterns on the small catchment scale estimated using unsupervised multiple regression,” https://doi.org/10.1002/vzj2.20258. Photo credit: Ingmar Schröter (CC-BY-SA 4.0).
{"title":"Cover Image, Volume 22, Issue 4","authors":"","doi":"10.1002/vzj2.20271","DOIUrl":"https://doi.org/10.1002/vzj2.20271","url":null,"abstract":"<b>On the cover</b>: A 3D data visualization of the elevation in the Schöfertal catchment (Germany). The digital elevation data are the primary source of information to quantify the data-related uncertainty of spatial soil moisture patterns estimated using an unsupervised multiple regression approach. See Paasche et al., “Quantification of data-related uncertainty of spatially dense soil moisture patterns on the small catchment scale estimated using unsupervised multiple regression,” https://doi.org/10.1002/vzj2.20258. Photo credit: Ingmar Schröter (CC-BY-SA 4.0).","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"61 5","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138505131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maintaining the editorial standards of a scientific journal is the primary task of the journal editors. Their task is made much easier with the help of colleagues who are invited to review manuscripts. Through their critical comments and helpful suggestions, these volunteer reviewers have done much to maintain and further the quality of research reported in Vadose Zone Journal. The members of the VZJ Editorial Board express their appreciation to the following individuals who reviewed one or more manuscripts during the past year. Every effort was made to compile an accurate list from our records. We extend our apologies and thanks to any reviewers whose names have not been included.
{"title":"Thanks to Reviewers, Vadose Zone Journal, 2022","authors":"","doi":"10.1002/vzj2.20261","DOIUrl":"https://doi.org/10.1002/vzj2.20261","url":null,"abstract":"Maintaining the editorial standards of a scientific journal is the primary task of the journal editors. Their task is made much easier with the help of colleagues who are invited to review manuscripts. Through their critical comments and helpful suggestions, these volunteer reviewers have done much to maintain and further the quality of research reported in Vadose Zone Journal. The members of the VZJ Editorial Board express their appreciation to the following individuals who reviewed one or more manuscripts during the past year. Every effort was made to compile an accurate list from our records. We extend our apologies and thanks to any reviewers whose names have not been included.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45246436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bromide is a frequently used conservative tracer in soil leaching studies, including studies on contaminant leaching from arable topsoils. However, bromide often does not behave conservatively. Biogeochemists have known for many years that in natural soils, bromide is converted into organic bromine in a process known as bromination. However, bromination is seldom used as an explanation of non‐conservative leaching behavior by soil hydrologists. In a controlled small‐scale lysimeter study with arable soil we demonstrate such nonconservative behavior of bromide in opposition to control columns with fine gravel/coarse sand. By combining a literature review with the lysimeter study, we demonstrate the potential importance of bromination in topsoil and that bromination cannot be ignored, when interpreting bromide tracer experiments in arable soils. We also highlight the need for further studies on the processes of bromination and remineralization, to be able to account for these when conducting bromide leaching assessments.
{"title":"Bromide reactivity in topsoil: Implications for use as a “conservative” tracer in assessing quantity and quality of water","authors":"C. Albers, A. Rosenbom","doi":"10.1002/vzj2.20260","DOIUrl":"https://doi.org/10.1002/vzj2.20260","url":null,"abstract":"Bromide is a frequently used conservative tracer in soil leaching studies, including studies on contaminant leaching from arable topsoils. However, bromide often does not behave conservatively. Biogeochemists have known for many years that in natural soils, bromide is converted into organic bromine in a process known as bromination. However, bromination is seldom used as an explanation of non‐conservative leaching behavior by soil hydrologists. In a controlled small‐scale lysimeter study with arable soil we demonstrate such nonconservative behavior of bromide in opposition to control columns with fine gravel/coarse sand. By combining a literature review with the lysimeter study, we demonstrate the potential importance of bromination in topsoil and that bromination cannot be ignored, when interpreting bromide tracer experiments in arable soils. We also highlight the need for further studies on the processes of bromination and remineralization, to be able to account for these when conducting bromide leaching assessments.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46313786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Newell, Emily B. Stockwell, Jessica Alanis, D. Adamson, Kenneth L. Walker, R. Anderson
Soil‐to‐groundwater contaminant mass discharge (Md) is the authoritative metric defining source strength at sites impacted by per‐ and polyfluoroalkyl substances (PFAS) and is increasingly being reported. Accurate estimates of groundwater recharge at representative spatial scales, however, is critical to quantitatively estimating Md, which to date has received comparatively little attention relative to PFAS‐specific partitioning and retention processes within unsaturated zone source areas despite a plethora of available literature. The objective of this review is to summarize the concept of Md as it applies to PFAS‐impacted sites, present standardized terminology, and collate published literature on groundwater recharge for a practitioner‐level summary of practical methods. Critically, the primary aim is to reduce uncertainty in recharge (and, thus, Md) estimates commensurate to a given site management application (i.e., the data quality objective process). Therefore, we propose a tiered system of increasing cost, complexity, and certainty depending on specific project requirements and site conditions and recommend applicable recharge methods for each tier based on these factors. Ultimately, a framework is presented for the assessment of PFAS‐impacted source areas based on the concept of Md.
{"title":"Determining groundwater recharge for quantifying PFAS mass discharge from unsaturated source zones","authors":"C. Newell, Emily B. Stockwell, Jessica Alanis, D. Adamson, Kenneth L. Walker, R. Anderson","doi":"10.1002/vzj2.20262","DOIUrl":"https://doi.org/10.1002/vzj2.20262","url":null,"abstract":"Soil‐to‐groundwater contaminant mass discharge (Md) is the authoritative metric defining source strength at sites impacted by per‐ and polyfluoroalkyl substances (PFAS) and is increasingly being reported. Accurate estimates of groundwater recharge at representative spatial scales, however, is critical to quantitatively estimating Md, which to date has received comparatively little attention relative to PFAS‐specific partitioning and retention processes within unsaturated zone source areas despite a plethora of available literature. The objective of this review is to summarize the concept of Md as it applies to PFAS‐impacted sites, present standardized terminology, and collate published literature on groundwater recharge for a practitioner‐level summary of practical methods. Critically, the primary aim is to reduce uncertainty in recharge (and, thus, Md) estimates commensurate to a given site management application (i.e., the data quality objective process). Therefore, we propose a tiered system of increasing cost, complexity, and certainty depending on specific project requirements and site conditions and recommend applicable recharge methods for each tier based on these factors. Ultimately, a framework is presented for the assessment of PFAS‐impacted source areas based on the concept of Md.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45916523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}