Progress 06/01/24 to 05/31/25
Outputs
Target Audience:Undergraduate students at Penn State: I served as sole Instructor of Record for SOILS 071 (Environmental Sustainability) at Penn State for the 2025 Spring Semester. A three-credit general education course in the natural sciences, the class reached 24 undergraduate students across a wide range of majors, programs, and class levels. The class connected sustainability issues, in particular related to agriculture and food systems, to soil science. In addition to lecture sessions, field trips and a greenhouse experiment delivered enriching hands-on experiences to the classroom, allowing diverse students to engage in the practice of research and inquiry when they otherwise might not have the opportunity to do so in their standard course of study. Undergraduate students at York College of Pennsylvania: I presented a guest lecture for an undergraduate level soil science class at York College of Pennsylvania (YCP; November 2024), a Primarily Undergraduate Institution in South-Central Pennsylvania. The class consisted of 10 students in the Environmental Horticulture Program at YCP. For the talk, I provided an introductory lesson about the use of cover crops in agroecosystems and their impact on nutrient cycling processes. Then, I shared results from my analysis of nitrogen leaching patterns from cover cropped agricultural systems. I incorporated active learning activities to promote student engagement, where students designed their own mixture of cover crop species to achieve ecosystem services that benefit agricultural practitioners. Academics in crop, soil, and agronomic sciences: I presented results from my analysis of nitrogen leaching patterns from cover cropped agricultural systems at the ASA-CSSA-SSSA International Annual Meeting in San Antonio, TX (November 2024). My oral presentation reached about 20 conference attendees, including fellow graduate students and faculty at various institutions. These efforts further developed my skills in science communication to an academic audience and initiated fruitful discussion with peers about research methods and agroecological theory. I was awarded First Place in the student competition for the Soils and Environmental Quality Division of the Soil Science Society of America (SSSA). Farmers and agricultural professionals in the Northeast US: I co-presented a workshop at the Pasa Sustainable Agriculture Conference in Lancaster, PA (February 2025). The three-hour workshop reached over 40 attendees, which included agricultural professionals from throughout the Northeast US. These efforts intended to deliver research insights into the hands of agricultural practitioners and land managers, reducing barriers to the accessibility of scientific research. Further, these efforts prompted engaging discussions about the applications of research findings for management decision-making. Agricultural professionals in Pennsylvania: I presented results from my collaborative project with Pasa Sustainable Agriculture, a non-profit organization based in Pennsylvania that reaches farmers and agricultural professionals throughout the Northeast US. I delivered two presentations to staff of Pasa Sustainable Agriculture (July and December 2024); in these presentations, I shared results from my analysis of survey data related to management decision-making among the Pasa farmer network and insights from the case studies I developed to highlight successful examples of adaptation to changing precipitation and temperature conditions by local farmers. These presentations aimed to support staff of the organization in their outreach and technical assistance efforts that aid farmers in the Northeast US. I also shared similar presentations to the Penn State Fruit and Vegetable Extension Team (March and May 2025). In doing so, I aimed to inform Penn State Extension professionals about farmer perceptions of and experiences with management practices that adapt to changing precipitation and temperature conditions. This included discussion of barriers to adoption of new practices and knowledge gaps that can be filled with Extension materials and programming in the future. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?I attended and presented at the ASA-CSSA-SSSA International Annual Meeting in November 2024 in San Antonio, TX. I also attended and presented at the Pasa Sustainable Agriculture Conference in February 2025 in Lancaster, PA. This conference is tailored toward farmers, agricultural professionals, and technical assistance providers, and allowed me to build connections with practitioners in the agricultural sector, an essential component of my professional development goals (Training Objective 2). I had the opportunity to develop my teaching skills for undergraduate audiences through my guest lecture at York College of Pennsylvania. Because YCP is a Primarily Undergraduate Institution (PUI), this experience was invaluable toward my development as a professor at a PUI (Training Objective 1). How have the results been disseminated to communities of interest?Results from the nitrogen leaching analysis were presented at the ASA-CSSA-SSSA International Annual Meeting in November 2024 in San Antonio, TX. The talk reached academics in the agricultural sciences. These results were also presented at the Pasa Sustainable Agriculture Conference in February 2025 in Lancaster, PA at a workshop on cover crop management. The workshop reached farmers and agricultural professionals in the Northeast US. Results from the collaborative project with Pasa Sustainable Agriculture were presented to the organization's staff (July and December 2024) and to the Penn State Fruit and Vegetable Extension Team (March and May 2025). Instructional materials were delivered to 24 enrolled undergraduate students in SOILS 071 course at Penn State University in Spring 2025. What do you plan to do during the next reporting period to accomplish the goals?In the next year (final project year), I will analyze stable isotope data from soil and soil extract samples to evaluate variation in microbial Carbon Use Efficiency (CUE) across gradients of soil texture. I will use the calculated CUE values to parameterize the Cycles model and improve the model's predictions of microbial C cycling based on soil texture. Then, I will use the Cycles model to simulate historical and future agricultural soil conditions, focusing on changes in soil C cycling as controlled by moisture variability, texture heterogeneity, and agricultural management. This summer, I will prepare and submit a manuscript for my analysis of nitrogen leaching patterns.
Impacts
What was accomplished under these goals?
Research Objectives The research aims of this project seek to identify how soil texture mediates the effects of precipitation change on agricultural soil carbon (C) dynamics. To achieve these aims, we pair laboratory and modeling approaches to understand soil texture and management practices as controls on C storage and loss in agroecosystems. In the prior reporting period (Year 1), I submitted soil and soil extract samples for carbon-13 isotopic analysis at Cornell Stable Isotope Laboratory. Soil and soil extract samples will be used to calculate microbial Carbon Use Efficiency (CUE) as a function of soil texture, filling a major gap in our understanding of variation in microbially-mediated C cycling processes in heterogeneous soil texture environments. Isotopic analyses were completed at Cornell in late April 2025. I will use these data to estimate CUE based on soil texture, allowing me to make further progress on Research Aims 1 and 2, where I will evaluate how projected future precipitation change will alter soil C storage in agroecosystems. I am using an agroecosystem model to simulate the effects of future precipitation change on microbial soil C cycling processes. A modeling approach, using the well-tested Cycles Agroecosystem Model, allows me to investigate a wide range of soil textures and varying agricultural management scenarios, ensuring the broad relevance and applications of knowledge generated from this project. In the past year, I began running test simulations of the Cycles model under a range of soil texture and agricultural management conditions to prepare for future climate simulations that will capture potential changes in agricultural soil C with frequent drying-rewetting cycles. These test simulations are being used to validate the carbon cycling processes in the Cycles model, ensuring that simulations under historic and future climate conditions will be able to approximate changes in soil C cycling dynamics. Specifically, I have been using historical management records from multiple long-term agricultural research stations to simulate changes in soil C storage as a result of various tillage and cropping system treatments applied for ten or more years at these sites. Preliminary results indicate that the Cycles model is able to generate realistic estimates of C turnover and storage rates, while also closely simulating reported yields at these long-term experimental sites. Additionally, I worked with collaborators to identify an ensemble of nine future climate models that will be used as the source of climate data for my simulations. Future climate data were retrieved for the years 2051-2099. I will complete the model validation process this summer and will initiate simulations under future climate conditions by early fall. These steps have allowed me to begin developing new competencies in simulation modeling, coding, and data management, which strongly supports my training objective to expand my interdisciplinary research skillset (Training Objective 1). This year, I continued making progress in my analysis of a long-term dataset capturing nitrogen (N) leaching from agricultural soils across gradients of soil texture and variability in annual precipitation. I used data collected during 10 years of cover crop management at a Penn State research station to investigate the effectiveness of diverse multi-species cover crop mixtures for reducing N leaching potential. In addition to biotic drivers of N leaching patterns related to cover crop stand characteristics, I investigated the influence of two abiotic drivers of leaching: soil texture heterogeneity and rainfall variability. This work complements my research into the impact of future precipitation change and soil texture on soil C cycling patterns. I completed data analysis in the spring, and am working to prepare a manuscript for submission this summer. This project augments my primary research objectives, allowing me to hone my data management, analysis, and statistical skills, which are essential to my development under Training Objective 1. Teaching Objectives In the fall semester of 2024, I sought out formal training in teaching by completing the Penn State University Schreyer Institute for Teaching Excellence's Course in College Teaching (CCT). The CCT is an eight-week course that supports instructors in their development as effective educators, teaching foundational skills in course design and pedagogy. Completion of the CCT is a major step toward achieving a teaching certificate from the Center for the Integration of Research, Teaching, and Learning; I plan to complete the remaining steps toward this teaching certificate by the end of the upcoming fall semester, which will position me as a competitive applicant to pursue my intended teaching-focused career path (Training Objectives 1 and 3). In the spring semester of 2025, I served as sole Instructor of Record for SOILS 071 (Environmental Sustainability), a general education course for undergraduate students at Penn State. Building off of course material delivered by previous instructors, I developed new and updated lecture materials, designed original assignments and course assessments, and guided a student-led greenhouse experiment. The greenhouse experiment, in particular, aligns with Training Objective 3, where I sought to develop teaching and mentorship skills to support undergraduate research experiences: students had the opportunity to engage in collaborative experimental design, data collection and discovery, and communication of results relevant to a broad audience, which are core elements of the Course-Based Undergraduate Research Experience (CURE) model. This activity fulfills my proposed teaching experience as part of this fellowship and provides essential training to become a successful professor at a Primarily Undergraduate Institution, where I intend to implement the CURE model to engage diverse students in enriching research experiences. Outreach and Extension Objectives This year, I completed a collaborative project with Pasa Sustainable Agriculture, a local agricultural non-profit organization. In this project, I applied qualitative research methods to analyze survey data collected by Pasa Sustainable Agriculture. The analysis focused on understanding perceptions of and experiences among farmers in the Pasa network related to management practices that adapt to changing precipitation and temperature conditions. This included current adoption of such practices and barriers to adoption. I also conducted two farmer interviews, where I asked farmers about the practices they currently apply on their farms and how those practices have helped them adapt to various climate impacts. I compiled each interview into a case study highlighting successful management changes to deal with warmer temperatures and more episodic precipitation patterns in the Northeast US; the case studies were published on the Pasa website in December 2024 and distributed at the Pasa Sustainable Agriculture Conference in February 2025. The research skills I gained through this activity support my development as a versatile researcher able to employ transdisciplinary methods (Training Objective 1). Further, I expanded my experience collaborating and communicating with agricultural practitioners, a valuable component of my career goal to produce and disseminate research that guides agricultural management decision-making (Training Objective 2).
Publications
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Progress 06/01/23 to 05/31/24
Outputs
Target Audience:Undergraduate students at Penn State: I implemented a lab and lecture module in SOILS 412W (Soil Ecology) at Penn State, reaching 25 undergraduate students in Penn State's Environmental Resources Management and Plant Sciences majors during two lab and three lecture sessions (Fall 2023). These efforts intended to bring enriching hands-on research experiences to the classroom, allowing diverse students to engage in the practice of research when they otherwise might not have the opportunity to do so. Graduate students and faculty members at Penn State: I presented preliminary findings from my analysis of nitrogen leaching patterns at the Penn State Ecology Program Colloquium in a talk titled Characterizing long-term patterns of nitrogen leaching as controlled by cover crop diversity and soil texture heterogeneity (February 2024). The talk reached 20 graduate students and four faculty members in the Ecology Program. These efforts developed my skills in science communication to a general Ecology audience and initiated discussion with peers about research methods and ecological theory. Farmers and agricultural professionals in Pennsylvania: I presented a workshop at Penn State's Annual Ag Progress Days, reaching 20 attendees over the course of two workshop sessions (August 2023). I also led a workshop at a Penn State Extension learning circle event for organic farmers, reaching 25 attendees during the all-day event (February 2024). These efforts intended to deliver research insights into the hands of agricultural practitioners and land managers, reducing barriers to the accessibility of scientific research. Further, these efforts prompted engaging discussions about the applications of research findings for management decision-making. Changes/Problems:My research objectives aim to understand how increasingly episodic precipitation and changes in drying-rewetting cycles will shape future agricultural C storage. I originally proposed to answer this question using a laboratory incubation project, where soil microcosms would substitute for field soil and moisture treatments would represent fluctuations in soil moisture under more frequent extreme precipitation. However, microcosms are an imperfect analogue of field soils, especially for capturing soil moisture dynamics: microcosms do not experience infiltration or drainage; soil evaporation is less realistic in a stable laboratory than in an exposed field; and there is no influence of vegetation. My previous experience using incubated soil microcosms to evaluate microbial respiration and CUE also revealed the challenges of managing microcosm soil moisture. Instead of a primarily-lab based approach, I have shifted to incorporate a modeling element to this project. Using the Cycles Agroecosystem Model, I will leverage insights into microbial CUE from the lab, while producing more accurate predictions of changing agricultural soil moisture and its potential consequences for soil C storage. Lab-generated predictions of microbial CUE based on soil texture will be used to refine microbial C cycling parameters within the Cycles model. Then, I will use global climate model data to simulate changes in future agricultural soil moisture. This approach will allow me to evaluate whether increases in extreme episodic precipitation and drying-rewetting cycles will negatively affect agricultural C storage and the potential for C sequestration. The conditions simulated in the Cycles model are an improvement on a soil microcosm approach, allowing me to represent the entire soil profile, agroecosystem water balance, and C cycle. Further, I will have the ability to consider more diverse soils, a wide range of starting soil organic matter levels, and different agricultural management scenarios. I have support from my dissertation co-advisor at Penn State, Dr. Armen Kemanian, who developed the Cycles model and can provide guidance as I build my computational skillset to successfully carry out model simulations for this project. Expanding my research toolkit beyond field- and lab-based studies to include modeling skills is key to my training objectives, and will better-position me for my chosen career path. What opportunities for training and professional development has the project provided?I attended the Pasa Sustainable Agriculture conference in February 2024 in Lancaster, PA. At the conference, I attended sessions on climate adaptation and mitigation, regenerative agricultural practices, and soil nutrient management. This conference is tailored toward farmers, agricultural professionals, and technical assistance providers, and allowed me to build connections with practitioners in the agricultural sector, an essential component of my professional development goals (Training Objective 2). How have the results been disseminated to communities of interest?Preliminary results from the nitrogen leaching analysis were presented at the Penn State Ecology Program Colloquium in February 2024. The talk reached a diverse group of graduate students from various ecological sub-fields, most of whom are not involved in agricultural research. What do you plan to do during the next reporting period to accomplish the goals? Research: In the next year, I plan to finalize estimates of microbial CUE based on soil texture, which I will compare to fixed CUE values used in the Cycles Agroecosystem Model. Next, I will parameterize the Cycles model with the texture-based CUE values to produce more accurate predictions of changes in soil C cycling and storage under climate change. I will identify a source of climate projection data for moderate and high future emissions scenarios and will access U.S. county-level crop and soil data for use in baseline and future climate simulations. I will begin running simulations of baseline climate conditions using the updated model CUE parameters, and will perform a model validation to ensure that model simulations are realistic before conducting future scenario simulations. This progress will add versatile computational skills to my research training. Additionally, I will complete the analysis of nitrogen leaching as controlled by cover crop species, soil texture, and precipitation variability, and will prepare a manuscript for submission. Teaching: In the spring semester of 2025, I will serve as Instructor of Record for SOILS 071 (Environmental Sustainability) at Penn State. This fall, I will prepare course materials, including elements from the CURE project I implemented in SOILS 412W in Fall 2023, building on my teaching experiences and developing my skills as an educator at the undergraduate level. Outreach and Extension: In summer 2024, I will complete the collaborative project with Pasa Sustainable Agriculture, including finalizing the analysis of survey data and creating two case studies based on farmer interviews. As a result of this project, I will strengthen my capabilities in outreach and agricultural extension activities.
Impacts
What was accomplished under these goals?
Graduate School Objectives: This year, I made significant progress toward the successful completion of my Ph.D., specifically by passing my Comprehensive Exam in November 2023 and completing all required coursework for my degree program in May 2024. Research Objectives: The overarching goal of my proposed research is to understand how soil texture mediates the effects of precipitation change on agricultural soil carbon (C) dynamics. To this end, I prepared soil and soil extract samples for carbon-13 isotopic analysis to calculate microbial Carbon Use Efficiency (CUE). Soil and soil extract samples will be used to calculate CUE as a function of soil texture, filling a major gap in our understanding of variation in microbially-mediated C cycling processes in heterogeneous soil texture environments. I prepared soil samples (108 samples dried and ground) and soil extract samples (486 samples freeze dried), which were submitted for carbon-13 isotopic analysis at Cornell Stable Isotope Laboratory. Estimates of CUE based on soil texture will allow me to make further progress on Research Aims 1 and 2, where I will evaluate how projected future precipitation change will alter soil C storage in agroecosystems. Originally, I proposed to pursue these research aims using a laboratory incubation experiment, where I would apply moisture treatments to soil microcosms that mimic predicted increases in episodic precipitation. However, microcosms are an imperfect substitute for field conditions, especially in terms of soil moisture dynamics. Further, the proposed moisture additions may not have adequately represented changes in the frequency and intensity of precipitation, especially the expected changes in drying-rewetting cycles with climate change. My previous research experience with laboratory incubations elucidated the challenges of managing and manipulating microcosm soil moisture, which further motivates a change in my choice of methods. Thus, instead of relying on a lab-based approach to capture changing soil moisture regimes, I have shifted my approach to use an agroecosystem model to simulate the effects of future precipitation change on microbial and soil C cycling processes. A modeling approach, using the well-tested Cycles Agroecosystem Model, allows me to investigate a wider range of soil textures, broadening the relevance and applications of the knowledge generated from this project. I will use the calculated CUE values described above to parameterize the Cycles model and improve the model's predictions of microbial C cycling based on soil texture. This represents an enhancement to the Cycles model, as well, which otherwise uses a constant value for microbial CUE that may not accurately reflect variation in CUE with texture. Additionally, I will be able to develop new competencies in simulation modeling, coding, data management, and analysis that will bolster my interdisciplinary research skillset; this development strongly supports my training objectives (Training Objective 1). I began running test simulations of the Cycles model under a range of soil texture, organic matter, and agricultural management conditions to prepare for future climate simulations that will capture potential changes in agricultural soil C with frequent drying-rewetting cycles. Augmenting my primary research objectives, I initiated an analysis of a long-term dataset capturing nitrogen (N) leaching from agricultural soils across gradients of soil texture and variability in annual precipitation. Using data collected during 10 years of cover crop management at a Penn State research station, I am investigating the effectiveness of individual cover crop species and diverse multi-species mixtures for reducing N leaching potential. I am also considering the effects of soil texture and precipitation, leveraging an in-field soil texture gradient and wide variation in annual rainfall at the research station. This year, I conducted a preliminary analysis of these data, which revealed that: all cover crop treatments reduced the risk of N leaching; reductions in leaching potential are most apparent in the winter and below 40 cm; and diverse mixtures of cover crop species are nearly as effective as the most effective monocultures in terms of reducing N leaching. While soil texture and precipitation appear to influence leaching in some treatments, these effects are variable and less pronounced than species effects. Through this project, I am strengthening my data management, analysis, and statistical skills, which supports my development under Training Objective 1 and preparation for my chosen career. I am also extending my experience examining the outcomes of interactions between soil texture and climate for soil nutrient cycling, looking beyond carbon to also include nitrogen dynamics. Teaching Objectives: In the fall semester of 2023, I made progress toward my goal of developing mentorship and teaching skills to support undergraduate research experiences (Training Objective 3). Based on the CURE (Course-Based Undergraduate Research Experiences) model, I planned and executed a CURE teaching module in SOILS 412W (Soil Ecology) for undergraduate students at Penn State. I collaborated with Dr. Denise Finney (collaborating mentor, Ursinus College) and Dr. Mary Ann Bruns (professor and lead instructor, Penn State) to design a two-part lab series and three-part lecture series on soil health. For this series, I compiled background materials to prepare students for the lecture and lab, designed a lab manual to carry out three soil health assessments, and created lab assessments to evaluate learning objectives. Outreach and Extension Objectives: This spring and summer, I pursued a collaboration with a local agricultural non-profit organization, Pasa Sustainable Agriculture. In this collaborative project, I am summarizing and analyzing survey data collected by Pasa Sustainable Agriculture to understand perceptions of and experiences with Climate-Smart Agriculture within the organization's network of farmers. I have developed new research skills to analyze survey data and apply qualitative research methods from the social sciences. In addition to the analysis of survey data, I began planning for two farmer interviews, where I will ask farmers about the climate-smart practices they apply on their farms and how those practices have helped them adapt to various climate impacts. Each interview will be compiled into a case study to highlight successful climate-smart agriculture in practice in the Northeastern US. I received IRB approval for the farmer interviews in May 2024. This project represents a significant training milestone toward my goal of becoming a professor at a Primarily Undergraduate Institution (Training Objective 1), where the ability to employ multi-disciplinary research methods and collaborate with non-academic entities will be invaluable. Additionally, this project relates to my goal of engaging with agricultural practitioners (Training Objective 2) to produce and communicate research that extends beyond academia. Also under Training Objective 2, I participated in and led activities through Penn State Extension. In August 2023, I presented a workshop at Penn State's Ag Progress Days Exhibition. In February 2024, I contributed to a workshop at a Penn State Extension learning circle for organic farmers. In the workshop, I guided participants through the process of hand texturing to determine soil texture on their fields, and we discussed the impact of texture on soil fertility.
Publications
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