2nd Place: Investigating the impacts of cover crop soil legacies on belowground multitrophic interactions in maize

Monday, November 14, 2022

11:18 AM – 11:30 AM PT

Location: Vancouver Convention Centre, Meeting Room 214

Presenting Author(s)

Olivia Trase

Graduate Student
Pennsylvania State University
University Park, Pennsylvania

Co-Author(s)

JA

Jared G. Ali

Associate Professor
Pennsylvania State University
University Park, Pennsylvania

The US has seen a resurgence in the use of cover crops over the last decade as a sustainable and economical solution for improving soil health. Recent research has highlighted the ability of cover crops to leave soil “legacies” which can impact the soil microbial community and reduce herbivore performance on subsequent cash crops. However, the benefits of these legacy effects are not generalizable across all cover crop species, cash crop species, or locations. Thus, for practical use, species-specific and location-based cover crop research is needed. To target an economically important system, we conducted a greenhouse experiment to study the effects of cover crops on corn and western corn rootworm (WCR) in Pennsylvania. We grew corn in soil which had been previously planted with pea, radish, triticale, a mixture of cover crops (pea, triticale, clover, and canola), or soil that had been left fallow. To understand changes to the microbiome, we collected soil before planting the corn and after five weeks of growth. We then added 20 neonate WCR to half the corn which fed for two weeks. Soil samples showed distinct fungal community differences between the cover crop treatments while changes in the bacterial community were most distinct between the initial soil collection and the collection after five weeks. Larvae recovered from corn grown after the fallow soil had lower survival, less weight gain and stunted development compared to other treatments. Results indicate that cover crops can leave biotic legacies that impact the soil microbiome and WCR performance.