Progress 06/01/20 to 05/31/24
Outputs
Target Audience:Researchers, stakeholders The target audience for this work will include academic researchers across the U.S. and across the globe. New indicators of soil health and soil microbial physiological activity will be of interest to academics and also the Soil Health Institute. Of particular interest is the effect of environmental and anthropogenic stressors on the soil microbiome. Other stakeholders interested in this work include commodity groups such as Cotton Incorporated or the Soybean Promotion Board. Changes/Problems:Research was severely impeded by the 2020 Coronavirus pandemic, which resulted in all non-essential research being suspended due to Covid-19. What opportunities for training and professional development has the project provided? University of Arizona Thesis, "Influence of inorganic and organic soil amendments on the soil microbial physiological activity." Thesis, "Evaluation of Microbial Physiological Activity Through the Use of the AMP Stress Index in the Context of Micro -Plastics and Soil Revitalization Post-drought. Presentation, University of Limerick, Ireland, "Influence of soil moisture stress on soil microbial health." Mississippi State University Thesis, Mississippi State University, "Investigating potential indicators of soil health through microbiome response to environmental and anthropogenic stressors". Presentation, Soil Science Society of America, Nov. 2022, "Defining Soil Health Through Microbiome Response to Environmental Stressors How have the results been disseminated to communities of interest? Presentation, University of Limerick, Ireland, "Influence of soil moisture stress on soil microbial health." Presentation, Soil Science Society of America, Nov. 2022, "Defining Soil Health Through Microbiome Response to Environmental Stressors What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Accomplishments: . University of Arizona Accomplishments Objective: Evaluate the influences of soil moisture and water activity on active and potentially active bacteria in soil as an indicator of soil health. The Adenosine Monophosphate (AMP) Stress Index was utilized as a new indicator of the physiological status of the soil microbial community.Soil moisture was shown to regulate soil microbial activity, with activity decreasing in moisture stressed soil. In contrast, moisture stressed communities were shown to increase activity within 5 minutes of the addition of water to the soil. Since the data is obtained within10-15 minutes, the assay provides a biological indicator of soil activity near-real time Objective: Evaluate the influence of micro-plastics on soil microbial activity Two experiments both utilizing two different soils were conducted. Polyethylene micro-plastics size 53-63 µm were added to each of the two soils and incubated for 10 days. Soil microbial physiological activity was evaluated via the AMPi Stress Index, heterotrophic plate counts and the dehydrogenase activity assay. Data showed no significant differences between the micro-plastic amended soils and the control (no micro-plastic) soils. A second series of experiments was conducted with smaller micro-plastics of size 1-4 µm diameter. After incubation over a 6-month period with monthly analyses, there was once again no significant differences between the micro-plastic amended soils, and the control (no micro-plastics) soils. Objective: Evaluate the influence of organic and inorganic fertilizers on soil microbial physiological activity We evaluated the influence of urea (inorganic fertilizer) and two organic soil amendments (glucose and biosolids) on soil microbial physiological activity in two soils using three assays: the AMP Stress Index; heterotrophic plate counts; and dehydrogenase activity. Results showed that urea had only a limited effect on microbial activity. In contrast, the addition of glucose to soil added organic carbon to soil which stimulated heterotrophic microorganisms. Biosolids contain both an organic matrix and nitrogen, such that when used as a soil amendment, soil microbial physiological activity was increased as expected. Of all 3 amendments (urea, glucose and biosolid), biosolids would be the most likely amendment to improve soil health. Mississippi State Accomplishments Overall: The purpose of this study was to assess the effects of environmental and anthropogenic stressors on the soil microbiome, with the aim of identifying measurable soil biological indicators. . Soil biological responses were analyzed via enzymatic response, microbial functional genes, and microbial community. Environmental factors such as soil moisture and organic matter showed significant influence on the microbiome with each selected biological indicator showing importance. Anthropogenic factors provided various responses dependent largely on the nature of the soil amendment. This study demonstrates that in addition to traditional soil health indicators, soil biological indicators should be included in the process of determining healthy soils. Objectives Evaluate the influence of soil, moisture, and water activity on the active and potentially active bacteria in soil, as an indicator of soil health. Environmental Stressors: Traditional indicators of soil health have previously not taken into consideration the biological aspect of soil. Using the selected biological indicators to analyze the described environmental stressors, organic matter and soil moisture levels provided a mensurate response from the microbiome. Water activity (water directly available to biological life) was shown to be an important indicator of the microbiome's health under extreme conditions related to low moisture, and was highly related to soil type, with clay soils not demonstrating any effect. The 16S and 18S gene abundance assay using quantitative PCR showed support as an effective and potentially reliable indicator of soil health. Finally, enzyme analysis did provide some important evidence of biological soil health especially amongst β-glucosidase and n-acetylglucosaminidase associated with organic matter. Furthermore, while we focused on a wide variety of measurements, there is a substantial depth of unexplored genes, enzymes, and targeted and shotgun sequencing which may elucidate many of these interactions. Overall, the methods used in these experiments show that the influence of environmental stressors on the microbiome, such as organic matter and soil moisture, do influence soil biological health. Evaluate the influence of agricultural soil amendments on soil health including inorganic fertilizer, organic fertilizer, and microplastics. Anthropogenic Stressors: Using the selected biological indicators to analyze the described anthropogenic stressors, only fertilizer inputs and glucose amendments (both at the microcosm scale) resulted in a mensurate response from the microbiome. Of the selected potential indicators tested in this study, none have been shown to be effective in determining biological soil health under the described anthropogenic stress situations. While the microplastic experiments (small plot-scale and microcosm scale) were only minimally statistically significant, this lack of significance is important as microplastic interactions in the soil are not yet fully understood. While beta diversity did show evidence of change within long term fertilizer conditions, only a general evaluation was given leaving the positive or negative effects of treatment unknown. Because of this, the importance of using 16S rRNA beta diversity metrics from a soil health perspective is undetermined. Water activity was shown to be an important indicator of the microbiome's health under extreme conditions related to low moisture conditions and microplastic exposure. As stated previously, water activity appears to be highly related to soil type and is only useful as an indicator of biological health under drought conditions. Overall, the methods used in this experiment show that the influence of anthropogenic stressors on the microbiome, such as synthetic soil amendments and microplastic pollution, are more complex and warrant additional research. Evaluate soil health utilizing molecular approaches. The 16S and 18S rRNA gene abundance assay, using quantitative PCR showed support as an effective and potentially reliable indicator of soil health. Addition of this assay would be economically feasible and relatively quick to perform and interpret, providing a valuable tool for microbial soil health analysis. While beta diversity, as measured through 16S rRNA high throughput sequencing, did show evidence of change within long term fertilizer conditions, it is a costly assay and requires a great bit of expertise to interpret. Because of this, the importance of using 16S rRNA beta diversity metrics or any other metrics from sequencing for soil health is undetermined. While some significance was also found amongst the functional genes, the consistency in response of these selected functional genes may not be high enough to suggest use as a soil health indicator strategy.
Publications
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Progress 06/01/22 to 05/31/23
Outputs
Target Audience:1) University academics 2) County extension agents 3) General community at large Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Three masters students were trained during this study How have the results been disseminated to communities of interest?Presentations on the work were made at the University of Arizona Water and Environmental Technology Center Annual Meeting What do you plan to do during the next reporting period to accomplish the goals?Conduct soil health analyses on real world agricultural soils including DNA extractions and metagenomic analyses.
Impacts
What was accomplished under these goals?
The influence of inorganic fertilizer, organic fertilizer, anthropogenic compoundand wet/drying cycles on soil health was evaluated in laboratory studies. Amendments included: soil water in wetting /drying cycles; inorganic fertilizer as urea; organic fertilizer as glucose and biosolids; and anthropogenic compounda as microplastics. Analyses indicative of soil health included: heterotrophic plate counts; dehydrogenase activity; the AMP Stress Index; metagenomics; and soil enzyme anaiyses. Data showed that the influence of soil moisture stress as soils were dried adversely affected soil health, whilesubsequent rewetting restored soil health to their original level within a time period of 10 minutes. The influence of urea amendment had little influence on soil health since no organic substrate was added via urea, resulting in only autotrophic communities such as ammonifiers and nitrifiers being impacted.. In contrast addition of organic fertilizers such as glucose or biosolids resulted in major impacts on the soil heterotrophic populations.Short term effects of microplastic addition to soil showed no influence on soil health. With respect to metagenomic and enzyme analysis: Environmental and anthropogenic stressors affected the soil biology, either noticeable through enzymatic or genetic analyses. 16S and 18S gene abundance levels are an important addition to "traditional" soil health indicators, and offer a cheap addition to a typical soil health assessment. Functional gene abundance levels and enzyme analysis are not effective soil health indicators, possibly due to being too targeted at one particular biogeochemical pathway or potential. High throughput sequencing appears promising, but still requires too much interpretation to be effective as a soil health indicator.
Publications
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Progress 06/01/21 to 05/31/22
Outputs
Target Audience:1) University academics 2) County extension agents 3) general community at large Changes/Problems:The only problem was the delay caused by SARS-CoV-2 pandemic. What opportunities for training and professional development has the project provided?Two masters graduate students were trained in basic research essentials as they conducted the laboratory studies. How have the results been disseminated to communities of interest?Results were disseminated through participation in a Soil Health Workshop which was open to university faculty and staff , as well as extension workers and members of the community at large. Data have also been presented at the Arizona Water and Environmental Technology Center meeting in Tempe Arizona. What do you plan to do during the next reporting period to accomplish the goals?1) Continue soil amendment lab studies looking at the effects of biosolids and algae on soil health. 2) Analyse agriculturalsoils associated with various crops and look for correlations with crop yields.
Impacts
What was accomplished under these goals?
The influence of various soil amendments on soil microbial activity and functionality was evaluated in laboratory studies, Amendments included; soil water in wetting/drying experiments; inorganic fertilizer in the form of ammonia; oganic amendments as glucose; and microplastics. Analyses indicative of soil health included: heterotrophic plate counts; dehydrogenase activity; the AMP Stress index; metagenomics and soil enzyme analyses. Overall progress was impeded by the Coronavirus pandemic which resulted in non essential research being barred at the university.
Publications
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Progress 06/01/20 to 05/31/21
Outputs
Target Audience: Environmental Protection Agency (EPA) California Association of Sanitation Agencies (CASA) Northwest Biosolids European Biosolids Conference Universities Wastewater utilities Changes/Problems:COVID-19 could adversely influence the progress of research. What opportunities for training and professional development has the project provided?One Ph.D. student and one M.S student have been trained to conduct wastewater-based epidemiology. Specific training in viral nucleic acid extraction and qRT PCR was accomplished as the students pursued their degrees. How have the results been disseminated to communities of interest?Results and data have been disseminated via two peer reviewed publications. In addition, oral presentations have included 12 webinars and seminars, nationally and internationally. Audiences have included: Centers for Disease Control; California State Water Board; California Association of Sanitation Agencies; Ohio State University; University of Arizona; European Biosolids Conference. What do you plan to do during the next reporting period to accomplish the goals? Continue wastewater-based epidemiology studies Model existing PFAS data to evaluate and predict leaching of PFAS analyses through soil Evaluate the influence of land application of biosolids on soil health
Impacts
What was accomplished under these goals?
PROGRESS OF WORK AND PRINCIPAL ACCOMPLISHMENTS Objective 1: Conduct Wastewater Based Epidemiology for the Detection of Coronavirus Additional Coronavirus Research Underway at the University of Arizona Wastewater-based epidemiology has potential as an early-warning tool for determining the presence of COVID-19 in a community. The University of Arizona (UArizona) utilized WBE paired with clinical testing as a surveillance tool to monitor the UArizona community for SARS-CoV-2 in near real-time, as students re-entered campus in the fall. Positive detection of virus RNA in wastewater lead to selected clinical testing, identification, and isolation of three infected individuals (one symptomatic and two asymptomatic) that averted potential disease transmission. This case study demonstrated the value of WBE as a tool to efficiently utilize resources for COVID-19 prevention and response. Thus, WBE coupled with targeted clinical testing was further conducted on 13 dorms during the course of the fall semester. In total, 91 wastewater samples resulted in positive detection of SARS-CoV-2 RNA that successfully provided an early warning for at least a single new reported case of infection (positive clinical test) amongst the residents living in the dorm. Overall, WBE provided to be an accurate diagnostic for new cases of COVID-19 with an 82.0% positive predictive value and an 88.9% negative predictive value. Increases in positive wastewater samples and clinical tests were noted following holiday-related activities. However, shelter-in-place policies proved to be effective in reducing the number of daily reported positive wastewater and clinical tests. This case study provides evidence for WBE paired with clinical testing and public health interventions to effectively contain potential outbreaks of COVID-19 in defined communities. ACCOMPLISHMENTS WBE reduced the extent of exponential spread of COVID-19 Lives saved University of Arizona successfully remained open for the whole of the Fall 2020 semester Objective 2: Evaluation of PFAS in Class B Biosolids and Land Application Sites. Concern over the fact that biosolids contain PFAS, led to a moratorium being imposed on land application of biosolids in Pima County, Arizona on January 1, 2020 (Pima County, 2020). This action, enacted by the Pima County Board of Supervisors, doubled management costs for biosolids and has been the impetus for this current study. The goal of this study was to fully evaluate the potential impact of land application of biosolids on PFASs incidence in soil, and the potential for groundwater contamination by PFAS. This objective was able to be accomplished through a unique situation that had evolved in Pima County Arizona. Annual land application of Class B biosolids was initiated in 1984, and continued through 2019. Land application in Arizona is allowed on permitted lands registered with the Arizona Department of Environmental Quality and require annual documentation of loading rates and biosolids quality. Since biosolids are known to contain PFASs, loading rates allowed for the incidence of accumulated PFASs in soil to be determined following long-term application of known amounts of biosolids. Until 2014, the biosolids contained 3 to 7% solids and the material was applied via surface spraying or soil injection to a depth of 1 foot. From 2014 through 2019, cake biosolids at 14% solids were applied and disked into the soil at a depth of 1 foot. A field study was conducted in Pima County, AZ, to investigate the impact of long-term land application of biosolids on PFAS presence in soils. The study involved multiple agricultural plots that have received annual land application of Class B biosolids from 1984 to 2019. Depth-discrete soil samples were collected from the plots. Biosolids samples and samples of groundwater used for irrigation were also collected. Concentrations measured for 18 PFAS were evaluated to assess incidence rates and potential impact on groundwater. No PFAS analytes were detected at any of the three sampling depths for the soil samples collected from undisturbed sites with no history of agriculture, irrigation, or biosolids application (background control sites). Concentrations of PFAS ranging from non-detect to 1.8 μg/L were measured in soil samples collected from sites that were used for agriculture and that received irrigation with groundwater, but never received biosolids. Similar levels of PFAS were measured for soils collected from the agricultural fields that received biosolids applications. PFOS was observed at the highest concentrations, followed by PFOA. PFAS concentrations in soil attenuated dramatically with depth. Overall, attenuation was >90% at the 6 foot soil depth regardless of the biosolid loading rate. These results indicate that the irrigation water was likely the most important source of PFASs present in the soils for all of the study sites.
Publications
- Type:
Journal Articles
Status:
Under Review
Year Published:
2021
Citation:
Betancourt, W.W., Schmitz, B.W., Innes, G.K., Prasek, S.M., Pogreba Brown, K.M., Stark, E.R., Foster, A.R., Sprissler, R.S., Harris, D.T., Sherchan, S.P., Gerba, C.P., Pepper, I.L. 2021. COVID-19 containment on a college campus via wastewater-based epidemiology, targeted clinical testing and an intervention. Sci. Tot. Environ. In Review.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2021
Citation:
Pepper, I.L., Brusseau, M.L., Prevatt, J. et al. 2021. Incidence of PFAS in soil following long-term application of Class B biosolids: A Southern Arizona Case Study. Sci. Tot. Environ. In Review.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Schmitz, B.W., Innes, G.K., Xue, J., Gerba, C.P., Pepper, I.L., Sherchan, S. 2020. Reduction of erythromycin resistance gene erm (F) and Class 1 integran-intergrase genes in wastewater by Bardenpho treatment. Wat. Environ. Res. 92(7):1042-1050.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
2020. CASA Wastewater-Based Epidemiology update (on-line).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
2020. 25th European Biosolids and Organic Resources Conference: Fundamentals of WBE (on-line).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
2020. Ohio State Seminar: Wastewater-Based Epidemiology for Tracking the Prevalence of SARS-CoV-2 in a Community (on-line).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
2020. Northwest Biosolids: SARS-Co-V-2 in Wastewater (on-line).
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