From North Carolina to ISU – Meet Preston

Preston Marrable

It’s summer, and we welcome another class of Undergraduate Research Interns. This year we have three interns. Today, meet Preston Marrable from North Carolina Agricultural and Technical State University. Preston will be working with RegenPGC CoPD Dr. Shuizhang Fei.

Preston’s goals for the summer are to “gain more knowledge and strengthen my work ethic and attention to detail. As much as I want to improve on a professional level, I also want to build friendly relationships with my fellow peers.”

We are pleased to welcome Preston to Iowa State University,  where we know he will learn a lot with Dr. Fei!

Meet Preston Marrable

Brief Bio. I grew up in Los Angeles while moving around Southern California as a kid. I currently live in North Carolina, and I attend North Carolina Ag & Tech State University as a rising junior. My favorite subjects are English and History. My personal hobbies are cooking, exercise, and listening to music. Something unexpected about me is that I went to Japan last year, and I enjoyed every minute of it.

Why I applied… I applied to the program because I want to gain research experience in STEM and mathematics. I also want to gain professional insight and experience by building a coalition of connections among my Iowa State colleagues before, during, and after the program has finished.

My expectations for the REU program include… I want to gain more knowledge and strengthen my work ethic and attention to detail. As much as I want to improve on a professional level, I also want to build friendly relationships with my fellow peers.

Malcolm Yusuf St Cyr completes his Master’s degree

Malcolm Yusef St Cyr Headshot

Today, we congratulate RegenPGC Graduate Education Community member Malcolm Yusuf St Cyr for his successful thesis defense and completion of his Master’s studies at Iowa State University under the mentorship of RegenPGC CoPd Dr. Marshall McDaniel. Learn more about Malcolm’s thesis, Perennial ground covers: A mitigation strategy to nitrous oxide (N₂O) emissions for maize cropping systems, at www.regenpgc.org/wp-content/uploads/2026/05/2026-05-19-StCyr-OFFICIAL-THESIS.pdf

ABSTRACT
Agricultural intensification in the U.S. Midwest has led to widespread of nitrogen (N) losses through nitrate (NO₃⁻) leaching and nitrous oxide (N₂O) emissions, two processes that threaten water and atmospheric quality. Traditional winter cover crops (WCCs) have proven to be effective in reducing NO₃⁻ leaching but remain limited in adoption due to economic and management challenges. Perennial ground cover (PGC) systems integrate non-leguminous perennial grasses in between annual row crops offering a potentially optimized alternative that maintains continuous soil cover without requiring annual replanting. However, their influence on soil nitrous oxide emissions and soil nitrogen and carbon pools remain poorly explored. In this study we used three PGC treatments: 1) Zea mays L. without PGC (Maize Control), 2) maize with Poa bulbosa, a summer-dormant grass commonly called bulbous bluegrass (Maize+BBG), and 3) maize with Poa pratensis, or Kentucky bluegrass (Maize+KBG) to analyze the impact of PGC on N₂O emissions and soil N and C pools. Both PGC treatments reduced interrow cumulative N₂O emissions by 38–81% relative to the control in both years (p < 0.01), although row-position emissions were more variable and influenced by fertilizer placement. Despite these consistent interrow reductions, field-level cumulative N₂O emissions were not significantly different among treatments in either year. Overall, our results indicate that PGC does not affect field-level soil N₂O emissions, while maintaining similar levels of plant-available N, and had no effect on maize yield.

It’s raining awards!

Memis Bilgici Award

They keep coming! Here is another award for a member of our RegenPGC Graduate Education Community. This time, it’s Memiş Bilgici who received an Iowa State University Research Excellence Award (REX).

Per the University, the award’s purpose is to “[…] recognize outstanding research accomplishments as documented in their dissertations. These students are also expected to be academically superior and able not only to do research but also to develop a well-written product. The intent of REX program is to recognize “the best of the best” graduating students who have submitted theses and dissertations.”

Congratulations to Memiş and his supervisor, Prof. Thomas Lübberstedt this significant achievement and recognition.

From Memiş: “I am deeply grateful to my supervisor, Prof Thomas LübbLübberstedtd to the RegenPGC community, with whom I have had the privilege to collaborate. I am proud of what we have accomplished together and excited to continue learning, building, and contributing to sustainable maize breeding, perennial ground cover systems, and controlled environment phenotyping.”

RegenPGC research team releases latest progress report

Great news! Our RegenPGC research team has just shared our latest progress report. This report, which highlights our research, education, and extension efforts from August to October 2025, is designed to be easy to follow.

This report keeps our agency funder, USDA-NIFA, in the loop, and it’s also a way for the public, who supports our work, to stay informed.

You can find the report on our website at https://www.regenpgc.org/wp-content/uploads/2026/02/2026-01-30-RegenPGC-YR-5-Q1-FINAL.pdf

Contact: Dr. Raj Raman, Iowa State University Dept. of Agriculture & BioSystems Engineering rajraman@iastate.edu

Hallie Sandeen graduates from the University of KY

Hallie Sandeen graduation photo standing in corn

This holiday season, we celebrate the graduation of another member of our Graduate Education Community, Hallie Sandeen. Hallie has earned her Master’s degree from the University of Kentucky, where she was mentored by Dr. Erin Haramoto, Co-Project Director of RegenPGC. Hallie’s thesis, “Evaluation of Poaceae Species and Suppression Application Methods for Perennial Groundcover in Corn,” will contribute to the perennial ground cover research portfolio that our project is developing.

Hallie is the fifth graduate student to complete their degree with support from RegenPGC.

Hallie Sandeen, December 2025, Crop Ecology & Management (Master’s, University of Kentucky) – Dr. Erin Haramoto

Jack Moran, June 2025, Crop Ecology & Management (Master’s, Iowa State University) –  Drs. Susana Goggi & Ken Moore

Oluwatuyi (“Tuyi”) Olowoyeye, June 2025, Ecosystem Services and Modeling (Ph.D, Iowa State University) – Dr. Amy Kaleita

Max Eness, May 2025, Soil Health & Nutrient Management (Master’s, Iowa State University) – Dr. Marshall McDaniel

Kaila Topping, 2023 May, Ecosystem Services & Modelling (Master’s, University of Wisconsin, Madison) – Dr. Rob Anex

RegenPGC Team releases Year 4 Q 4 progress report

RegenPGC Yr 4 Q 4 Progress Report Cover

If it’s not documented … is it really complete? Who knows. However, here is our RegenPGC Year 4 Q4 Progress Report, and there is no doubt that we are learning more every day about perennial cover crops. You can access the report at https://www.regenpgc.org/wp-content/uploads/2025/11/RegenPGC-Yr-4-Q4-Progress-Report.pdf.

The report is written in a bulleted, friendly format and divided by topics so you can find your perennial cover crop passion right away! Check out our Research Objectives and Themes:

Objectives: Obj. 1. Crop Ecology & Management, Obj. 2. Plant Breeding & Genetics, Obj. 3. Soil Health & Nutrient Management, Obj. 4. Ecosystem Services, Modeling, Obj. 5. Socioeconomic Impacts & Policy and Project Evaluation

Themes:  Research and Development, Extension, Education, and Commercialization

Learn more about Dr. Cynthia Bartel, RegenPGC policy specialist and dairy farmer

RegenPGC's Dr. Cyndi bartel on the farm

Cynthia Bartel is the ag policy specialist on our project, and yes, she knows policy, but that’s not all she knows about.

Hint… It’s also about the cows and a lot more. Dr. Bartel qualifies as an all-around Ag-Renaissance woman.  Learn more about Dr. Bartel in Wisconsin dairy farm embraces robots, health monitoring and intercropping (https://www.farmprogress.com/dairy-cattle/wisconsin-dairy-farm-embraces-robots-health-monitoring-boluses-and-intercropping)

SeedWorld names RegenPGC CoPD Dr. Susana Goggi a top 50 woman

Susan Goggi award flyer

RegenPGC CoPd Dr. Susana Goggi was recently recognized by SeedWorld magazine as one of thirty “high-impact women” in the US seed industry. According to SeedWorld, Dr. Goggi and her distinguished peers have “carved out space in a field long dominated by others, proving that grit, skill, and collaboration are the true markers of excellence. From the lab to the boardroom, from seed physiology to supply chain, they are rewriting what impactful leadership looks like in our industry.”

Having Dr. Goggi on our team, we could not agree more with this assessment! Learn more about Dr. Goggi and the SeedWorld high-impact women’s group at: Nielson, Aimee (2025, September 23). A league of her own: 30 high-impact women. SeedWorld. https://www.seedworld.com/us/2025/09/23/shes-in-a-league-of-her-own-3/

Another honor for the RegenPGC grad student community

Yes, we are a research project, but we never forget that we are in the business of educating the next generation. In the summer, we mentor prospective STEM Education school teachers [See more at: https://www.regenpgc.org/theme-3-education/2023-ret-reu-programs-copy/]. But, all year round, our team mentors a talented group of graduate students in our Graduate Education Community.

Today, we celebrate Memiş Bilgici from our Breeding & Genetics Objective[See more at: https://www.regenpgc.org/objective-2-plant-breeding-and-genetics/], who presented this poster and was awarded a travel grant to Hawai’i: (Bilgici Memiş, Yu-Ru Chen, & Thomas Lübberstedt. (2025, May 19–23). Do we need dedicated maize varieties for perennial groundcover systems? [Poster]. 2025 National Association of Plant Breeders Annual Meeting, Kona, Hawa’i, United States).

Learn more by reading Memiş’ Poster Abstract at https://napbannualmeeting.org/wp-content/uploads/2025/07/NAPB_2025_Booklet_Digital_VF2.pdf, Poster #50.

Reflections on a summer well spent

Philip working with a student

At RegenPGC, we are building the future of perennial grasses and the teaching profession by introducing existing and prospective science/stem educators to our research portfolio. Every summer, we participate in two crucial Iowa State University initiatives, the Research Experience for Teachers (RET) and Research Experience for Undergraduates (REU) programs.

The RegenPGC RET program allows middle and high school teachers to gain research experiences and form ongoing relationships with PGC scientists and graduate students. Our goal is for our RET participants to share their RegenPGC experiences with their students upon their return to the classroom and inspire young persons to learn more about STEM subjects.

The RegenPGC REU program provides opportunities to undergraduate students interested in future careers as STEM teachers to engage in a hands-on research project with a RegenPGC mentor and research team.

Both projects take place during the summer months, and RegenPGC collaborator Maureen Griffin and her team at the Iowa State University Office of Biotechnology lead the project.

Learn more about the essential truths and inspirations that our REU and RET participants were exposed to in 2025 in this overview piece.