Protocol Bait-lamina strips / preparation of 100 g substrate (dry mass) v1

Bait lamina strips are a standardized tool to assess the feeding activity of soil invertebrates in situ. The method uses PVC or plastic strips, typically 16 cm long, 6 mm wide, and 1 mm thick, that contain a series of evenly spaced holes (usually 16–20) along their length. These holes are filled with a standardized bait mixture that mimics natural soil organic matter, often composed of cellulose powder, bran, and activated carbon. For deployment, the strips are inserted vertically into the soil, exposing the bait-filled holes at varying depths. The strips are left in the field for a defined incubation period (e.g., 2–4 weeks to several months), during which soil invertebrates (mainly meso- and macrofauna such as enchytraeids, earthworms, collembolans, and isopods) may feed on the bait. After retrieval, the strips are carefully cleaned, and each hole is inspected under a stereomicroscope. Feeding activity is scored as “empty” (1) if the bait is consumed or “intact” (0) if not. The proportion of holes consumed provides a quantitative measure of soil faunal feeding activity, which can be compared across soil depths, seasons, habitats, and land-use types. Bait lamina strips are inexpensive, easy to standardize, and widely applicable in soil ecology, environmental monitoring, and land-use impact studies. In a nutshell, the bait-lamina method provides a rapid, in situ indicator of soil invertebrate feeding activity and related biological functions. It is widely used to compare activity across land uses, regions, and seasons (Kratz, 1998). Adding an organic textile dye to the substrate can improve contrast between bait and soil during scoring (Eisenhauer et al., 2014).