Performance of Native Wildflowers as Warm-Season Cover Crops: Impacts on Arthropod and Microbial Communities

Commodities

Practices

Small-scale farms in Middle Tennessee encounter persistent pest pressure and limited access to ecologically grounded pest-management strategies in the face of balancing production profitability with habitat stability. Pests contribute to 20-40% annual crop losses ¹, and increasing chemical inputs undermine soil microbial communities and beneficial insects, reducing long‑term biological services ^2,3. This project evaluates whether native warm-season cover crops can enhance plant-microbe-insect interactions to strengthen biological control, improve soil health, and support practical management options for small producers.

Using ecological data from replicated field plots on three working farms, we compare a traditional warm-season cover crop mix with a native forb/grass analog mix. We will assess soil microbial communities using PLFA-based GC-MS analysis to determine microbial biomass, functional groups, and stress indicators. Arthropods collected from pitfall traps and sticky cards will be identified to functional guilds to evaluate predator-prey dynamics. Data from vegetation surveys and pollinator observations will be integrated to determine how plant structure influences above and belowground responses as they occurred through the 2026 growing season.

Farmer interviews will document labor, cost, and feasibility considerations to ensure ecological findings align with operational realities. Results will be shared in partnership with Tennessee State University Extension through events and publication of fact sheets. This project provides an assessment of native cover crops as tools for reducing pest pressure, enhancing soil and habitat function, and improving the profitability of small farms.

The goal of this research is to analyze ecological data collected from established warm-season cover crop (CC) study plots to determine whether incorporating native species enhances beneficial arthropods, soil microbial function, and habitat provisioning in varying production systems (hay/honey, mixed-vegetable, cut-flower).

Specifically, this project will:

1. Analyze arthropod communities from preserved specimens to compare functional feeding groups and predator-prey ratios between traditional and native cover crops.
2. Evaluate soil microbial function using soil samples collected across key management periods, quantifying microbial biomass, respiration, and key phenotypic indicators.
3. Interpret plant community composition from completed vegetation surveys to determine how vegetation structure influences arthropod and soil microbial responses.
4. Gather farmer perspectives through interviews with collaborating producers to assess feasibility, cost-benefit considerations, and perceived ecological value of each cover crop treatment.
5. Share results with the public by collaborating with participating farmers, Tennessee State University (TSU) Cooperative Extension, and local Natural Resource Conservation Service (NRCS) agents to deliver outreach materials, demonstrations, and regionally relevant guidance.

These objectives provide a preliminary foundation for continued research into the development, refinement, and long-term evaluation of native cover crop mixes for sustainable pest management and soil health.