Effects of intercropping and fertilization on weed abundance, diversity and resistance to invasion

Summary

This paper aims to evaluate the effects of the cover crop type (Vicia villosa monoculture vs. V. villosa and Hodeum vulgare polyculture) and the type of fertilization (organic vs. chemical) on the structure of the weed community (biomass, number of species, diversity and evenness) and its invasibility through the experimental introduction of Brassica sp. seeds as a target invader species. Results show that weed biomass, species richness and diversity of the weed community are significantly reduced by inter-cropping, but are not affected by the type of fertilization. In organic plots, the density increases and the complementary pattern of polyculture resource use reduces weed abundance and Brassica sp. invasion, while the rapid emergence and fast growth of weeds can explain the Brassica sp. invasion resistance in monoculture. In contrast, chemical fertilization favours Brassica growth.