By Andi Anderson
New research from Iowa State University highlights how careful spacing between crops and groundcover can help farmers balance productivity with environmental protection. The study focuses on how corn reacts when grown near perennial groundcover, a system designed to keep soil covered year-round.
The research is led by Amina Moro, a doctoral student in crop production and physiology. Her work examines how corn responds to nearby groundcover and was published in the Journal of Agronomy under the title “Spatial Proximity to Perennial Groundcover Triggers Shade Avoidance Responses in Corn.”
“Perennial groundcover systems are very promising because they keep the soil covered year-round, improving soil health, reducing erosion and enhancing sustainability,” Moro said. “But farmers are hesitant to adopt them because of concerns about competition with corn, especially early in the season.”
Moro’s research shows that plants can sense nearby vegetation even before competing for water or nutrients. Corn reacts to changes in light quality, triggering a shade avoidance response.
“When corn detects changes in light quality, it interprets it as a sign that competition is approaching,” Moro said. “It responds by growing taller and reallocating energy toward vertical growth.”
While growing taller may seem helpful, it can cause weaker stems and an increased risk of lodging. Moro found that corn responses depend strongly on distance.
“We observed that corn begins to respond at very short distances,” she said. “At six centimeters, plants already initiated a shade avoidance response, but at 25 centimeters, they behaved as if there were no competition.”
When corn was in direct contact with groundcover, plant growth was significantly reduced. These findings show that spacing is critical, not simply the presence of groundcover.
Susana Goggi, professor of agronomy and Moro’s advisor, emphasized the broader importance of the research. “The use of perennial groundcover is a game-changer,” Goggi said. “It can reduce soil erosion, water runoff and nutrient loss. But it also creates microclimatic changes that can affect crop growth.”
The study identifies a practical solution. A buffer zone of about 25 centimeters allows corn to grow normally while still gaining soil protection benefits. Moro also notes that choosing corn hybrids less sensitive to shade signals can improve results.
“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.”
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Categories: Iowa, Crops, Sustainable Agriculture