Lawn and order: Impact of Asian jumping worms on turfgrass and soil health

Asian jumping worms (AJW, Amynthas spp., Megascolecidae), an invasive earthworm known for its ability to rapidly reproduce, alter soil by accelerating nutrient cycling, and decrease the biodiversity of native flora and fauna, are becoming an increasing concern in turfgrass ecosystems. This study investigates the impact of AJW on turfgrass health and soil ecology in four residential sites, each featuring heavily infested gardens adjacent to turf lawns. At each site, four transects originating from infested garden areas were established, with three quadrats per transect: one in the infested garden, one immediately outside in the turf, and one six meters into the turf. This setup resulted in 12 quadrats per site, providing a spatial gradient study of AJW impact.

Microarthropod abundance was assessed using Berlese funnel extractions on soil samples from each quadrat. Soil from each quadrat was analyzed for microbial extracellular enzymes that break down chitin, amino acids, and lignin. Soil chemical properties (organic matter, macronutrients, pH) and physical properties (aggregation, texture) were also measured. Turf health was assessed by measuring light reflectance and estimating weed percentage.

Initial hypotheses predict elevated microbial activity in AJW-infested soils due to increased nutrient availability, with decreased microarthropod abundance and reduced soil aggregation. Higher pH levels are anticipated in AJW-infested quadrats compared to turf areas. The study aims to determine the potential gradient effect of AJW from garden beds to turf lawns, highlighting the broader implications for turfgrass management and soil health in residential ecosystems.