Organic mulching boosts ground-dwelling predators in potato fields [Dataset and R code]

This repository contains data and R code from three large-scale field experiments (2021a, 2021b, 2022) in commercial organic potato fields near Göttingen, Germany. The trials compared different organic mulches (triticale–vetch, barley straw, grass silage) with unmulched controls and quantified their effects on ground-dwelling carabid beetles and spiders using pitfall trapping during and beyond the main growing season.​ In total, 11,504 adult carabids (40 taxa) and 2,399 spiders (38 taxa) were recorded, mostly identified to species level. Mulching—particularly with triticale–vetch—increased the abundance of several key predator species (e.g. Poecilus cupreus, Bembidion lampros, B. quadrimaculatum, Erigone atra, E. dentipalpis), and significantly altered community composition, while effects on diversity indices were inconsistent and no carry-over effects into the following year were detected.​ The repository provides species-level count data for all pitfall traps and sampling dates, together with R scripts for data cleaning (tidyverse), descriptive summaries, mixed model analyses (glmmTMB with DHARMa and multcomp), diversity and ordination analyses (vegan, indicspecies), and visualization (ggplot2 and extensions). These materials enable reproducible analysis of how organic mulching shapes predator communities in potato agroecosystems and support its evaluation as a conservation biological control measure in integrated pest management.