Unraveling the effects of different horticultural management practices on foliar arthropods and soil nematodes

Global horticultural production faces ecological and health challenges associated with excessive agrochemical use. Alternative practices, such as crop rotation, polyculture, and biological control, are promising, but their adoption remains limited. Here, we investigated the short-term responses of plant-associated arthropod and soil nematode communities, herbivory, and crop yield to the implementation of two alternative management strategies for onion production. A replicated field experiment was established involving conventional (onion monoculture with complete agrochemical use), integrated (onion and cabbage with organic compost and reduced agrochemicals), and agroecological (onion, cabbage, and bean with organic compost and biological control) treatments. Our results demonstrated significant short-term effects of management strategy on foliar arthropods, soil nematodes, and crop yield. Management strategies affected the foliar arthropod and soil nematode communities which were more similar between agroecological and integrated management plots and showed higher diversity and abundance than in conventional plots. Integrated management produced the highest total crop biomass, while onion yield was statistically similar between conventional and integrated management. Communities of foliar arthropods and soil nematodes influenced cabbage yield, but not onion yield. Overall, our findings highlight the potential of reduced agrochemicals and polyculture cropping in promoting biodiversity and beneficial plant-fauna interactions in agroecosystems without compromising crop productivity.