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.

New RegenPGC publication hits the “Streamosphere”

Chart

RegenPGC Ph.D. student Memiş Bilgici, joined by RegenPGC colleagues Sara Lira, Lucas Borras, Ken Moore & Thomas Lübberstedt, has authored a new academic publication for the academic journal Frontiers in Plant Science.

The article, Trends in stomatal density and size in maize hybrids representing 100 years of long-term breeding for yield* highlights four main research findings:

  • Modern hybrids had higher stomatal density but lower total stomatal pore area than historical hybrids.
  • Across 27 Pioneer hybrids, stomatal density was negatively correlated with stomatal size, length, width, and leaf area.
  • Over the past 100 years, the total stomatal pore area on leaves decreased, while stomatal density increased as leaf area declined, revealing a connection between these two patterns.
  • Total stomatal pore area was negatively correlated with release-year atmospheric CO2 concentration and temperature anomaly (°C) over the past century.

According to Memiş, “To the best of our knowledge, this is the first crop-focused study to show century-scale changes in stomatal traits associated with long-term maize breeding for yield.”

*Bilgici, Memiş, Ebrahimi, Elnaz, Prada de Miranda, Leticia, Lira, Sara, Borras, Lucas, Young, Thomas, Yavuz, Recep, Moore, Kenneth J., Dixon, Philip, & Lübberstedt, Thomas. (2026). Trends in stomatal density and size in maize hybrids spanning 100 years of long-term yield breeding. Front. Plant Sci., 17:1829321. https://doi.org/10.3389/fpls.2026.1829321

New research informs how corn and perennial groundcover can coexist

Amina Moro in the lab

Today, we honor RegenPGC Graduate Education Community member Amina Moro and her work on corn’s “Shade Avoidance Response.” Iowa State University – College of Agriculture and Life Sciences recognized Amina’s work by featuring her in the article, “New research shows finding the ‘sweet spot’ is key to successful groundcover systems.” See: https://www.cals.iastate.edu/news/2026/new-research-shows-finding-sweet-spot-key-successful-groundcover-systems

Amina’s work informs how corn behaves when perennial groundcover is located in proximity to it. As the article specifies, “The practical applications of this research are clear. By maintaining a small buffer zone – around 25 centimeters – farmers can prevent early stress signals in corn while still benefiting from soil protection.”

According to Amina, “Farmers do not have to choose between improving soil health and maintaining yield,” Moro said. “With the right combination of spacing, hybrid selection, and management practices, it is possible to design systems where corn grows efficiently while the soil remains protected.”

Learn more about the science behind Amina’s work in her recently published paper in the Journal of Agronomy, “Spatial Proximity to Perennial Groundcover Triggers Shade Avoidance Responses in Corn” (https://www.mdpi.com/2073-4395/16/7/729).

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.”

Summer research experience leads to growth

2025 REU Kylie Buchholz presents her research

One of our success stories at RegenPGC is our participation in Iowa State University‘s summer Research Experience for Undergraduates / Research Experience for Teachers programs. Each spring, Wartburg College hosts RICE Day, where students share research, internships, and creative endeavors they have completed. This past summer, I participated in the REU program and had the opportunity to work on Cameron Krumm’s research in Dr. Shuizhang Fei’s lab. Here is an update from Kylie Buchholz, a Wartburg student and a summer 2025 REU participant.

“After completing the REU, I presented this research at RICE Day this spring. This was a valuable opportunity for me that allowed me to share my experience with a wide range of faculty, students, and community members.

This engaged audience was deeply interested in my experience in the program. They were specifically interested in learning how this research connected to my future career in education. I was able to share multiple different lessons that I learned from my experience, many of which relate to the type of culture I want to create in my classroom.

By participating in this REU, I learned that having a positive attitude and cultivating a supportive community is essential for quality work to be produced. Additionally, this experience reinforced the importance of collecting many different data points before drawing a conclusion. These same things that I learned by participating in the REU are things that I will need to remember when I am shaping what I want my classroom to look like. Presenting the research I worked on this past summer at RICE Day was a great experience for me because it pushed me out of my comfort zone, helped me to reflect on what I want my classroom to be like, and allowed me to share this incredible research with those around me.”

Meet new grad student Zoe Gray

Zoe Gray headshot

Meet RegenPGC’s newest graduate stuent Zoe Gray. Zoe is a master’s student in soil science at the University of Missouri, where RegenPGC CoPd Morgan Davis serves as her advisor. Zoe previously obtained her bachelor’s in environmental science from the University of Missouri.

As an undergrad, Zoe joined the soil judging team, where I competed in numerous competitions that focused on soil chemistry, biology, morphology, physics, and genesis. During her time with the team, Zoe found a desire to learn more about soils and decided to pursue her master’s degree.

As a new member of the RegenPGC team (April 2026), Zoe’s research will focus on the hydraulic conductivity of soils within a perennial groundcover system compared to a system with no ground cover. She will be focusing on hydraulic conductivity as well as water retention curves.

Career Aspirations
After completing her Master’s, Zoe hopes to stay within the research realm and continue working in a lab space that strives to enhance agricultural methods with the integrity of the soil in mind.

Graduate Advisor
Dr. Morgan Davis (RegenPGC CoPd)

This is how we grow the future!

RegenPGC is a research program, and we define that term broadly, as we should. Every year, we help build the future by introducing existing and prospective science/STEM educators to our research portfolio.

We achieve this by participating in two crucial initiatives at Iowa State University: the Research Experience for Teachers (RET) and the Research Experience for Undergraduates (REU) programs. (https://lnkd.in/dC6HWes6). During the summer months, RegenPGC teachers and undergraduate interns become active members of our research team. This changes not only their lives but also positively impacts countless lives throughout their teaching careers as they apply their newfound knowledge directly to their classrooms.

Alex Haus, a 2025 Undergraduate Research Intern, is set to do the RegenPGC team proud when he presents his work at Wartburg College’s 15th RICE DAY (https://www.wartburg.edu/academic-affairs/rice/) on April 9, 2026. Alex’s poster, “How Perennial Groundcover Affects Maize Growth: Exploring Shade Avoidance Responses,” (https://www.regenpgc.org/wp-content/uploads/2026/03/RegenPGC-Poster-Template-med-QR.pdf), is a wonderful example of how interns can gain by working in a research team.

New publication focuses on grain yield

Grass trial Strips: Control, Bulbous Bluegrass & Kentucky Bluegrass

Here is our latest publication. The good news, lots of perennial ground cover info, and it’s open access! Click on the link below and you will be taken directly to the article.

  • Galland, Patrick D., Dutter, Cole R., Chen, Allen, Moore, Kenneth J., Fei Shui-Zhang. (2026). Summer-dormant, perennial groundcover has minimal effect on plant-available nutrients and no effect on maize yield. Agronomy Journal, 118, e70333. https://lnkd.in/g9nJPm6W OPEN ACCESS

Abstract
Conventional agriculture in the US Midwest has accelerated crop productivity but also contributed to undesirable environmental issues. Perennial groundcovers (PGCs), such as cool-season grasses intercropped in the maize (Zea mays L.) interrow, have the potential to reduce soil erosion rates and mitigate nutrient losses. However, work is still needed to select compatible PGC grasses to optimize the maize–PGC intercropping system. Our study assessed the compatibility of two grass species: Kentucky bluegrass (KBG; Poa pratensis L.; represented by three cultivars and one cultivar blend) and the summer-dormant bulbous bluegrass (BBG; P. bulbosa L.). We compared the effect of these PGCs on grain yield and three soil resources (soil water, plant-available nitrogen [PAN], plant-available phosphorus [PAP]) to that of the Control (no PGC). There were no differences in grain yield among the four KBG cultivars, so we focused on comparing the KBG, BBG, and Control. Both PGC species reduced PAN by 40%–50%, but only BBG reduced PAP by 19%, compared to the Control. KBG decreased maize yields by 28%–36% on average compared to the Control, and we surmised that lack of soil moisture was the major reason for this. For every 13 mm loss in soil water storage caused by PGC, there was a 1 Mg ha−1 loss in maize yield. The BBG treatment, however, showed little change in soil moisture and no decrease in grain yield relative to the Control. Our study shows that BBG can protect soil during winter yet has no negative effect on soil moisture and maize yield.

RegnPGC’s Richard Roth receives ISU Extension award

Richard Roth Headshot

Regen PGC Collaborator Dr. Richard Roth has received a faculty 2026 Early Achievement in Extension and Outreach Award from the College of Agriculture and Life Sciences at Iowa State University.

Dr. Roth is part of our RegenPGC Soil Health & Nutrient Management Objective, where he works closely with RegenPGC Graduate student Alioune Diop.

Dr. Roth is an Assistant Professor of Agronomy, an extension soil fertility specialist, and the co-director of the Field Extension Education Laboratory, His peers have recognized  Dr. Roth for exemplifying Iowa State University’s land-grant mission by translating applied agronomic research into actionable knowledge for farmers, industry professionals and the broader agricultural community.

His award states: “Roth’s approach to extension is grounded in science, driven by curiosity and shaped by a deep commitment to stakeholder engagement. He has made it a priority to connect with industry partners, listening carefully to their needs and tailoring his research and outreach to address real-world challenges. His work evaluating the effectiveness of various nitrogen inhibitor products is already proving to be of significant value – not only to the industry at large, but especially to producers seeking practical, science-based solutions to improve nitrogen use efficiency and environmental stewardship.”

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