Enhancing arthropod communities through plant diversified edge of kale cultivation

Plant diversification can increase organism abundance while reducing phytophagous insect activity in agricultural crops. We assessed arthropod diversity in fava beans (Vicia faba), fennel (Foeniculum vulgare), and marigolds (Tagetes patula) along the periphery of a kale plantation and examined the influence of their proximity to the kale cultivation. The study took place at the Centro Estadual de Diagnóstico e Pesquisa Florestal, Santa Maria, RS, Brazil. We collected plant samples from the periphery and cultivated kale plants at three distances from the edge: within two meters, 10 to 12 meters, and 20 to 22 meters. We recorded the number and biomass of marketable leaves from three harvests. A total of 618 arthropods were collected from plants along the periphery: Insecta (589), Arachnida (20), and Entognatha (9). Hemiptera was the most prevalent order (49.84%). Kale plants near the periphery experienced less predation from leaf beetles. Plants along the periphery hosted important predator groups as well as phytophages that can serve as alternative prey. Diversifying the periphery with fennel, fava bean, and marigolds shows promise as a strategy to enhance the arthropod community in kale cultivation, thereby acting as a conservative biological control.