Arable wildflowers have potential as living mulches for sustainable agriculture

ABSTRACT Background As agriculture has intensified, many once-common wildflowers have declined in arable landscapes, which has widespread implications for associated ecosystem services. The incorporation of sustainable practices, for example, growing living mulches (in-field, non-crop plant ground cover, maintained during the target crop growing season), can boost arable biodiversity, but few wildflower species have been utilised in this context. Aims Our aim was to determine the suitability of arable wildflower species, once considered weeds, for use as living mulches. Methods We first screened a number of arable wildflower species for germination when growing with a common cereal, barley (Hordeum vulgare). We then grew two (Centaurea cyanus and Scandix pecten-veneris) in pots in a glasshouse with and without barley, and grew barley alone to test the impact of the wildflowers on barley growth and biomass. Results Neither of the wildflowers significantly negatively impacted barley biomass. Barley initially facilitated germination in S. pecten-veneris, but ultimately suppressed the above-ground biomass of both wildflowers. However, both wildflower species were able to coexist alongside barley. Conclusions Our experiment provides evidence that wildflowers that were considered weeds in traditional agriculture have the potential to be grown alongside barley and could be incorporated as part of a living mulch.