Abstract
Ecological concepts derived from perennial grasslands suggest
multi-species cover crop mixtures maximize ecosystem function. However,
legacy effects of diverse cover crops on agricultural soil properties,
microorganisms, and crop yields remain unclear. To address this knowledge
gap, we planted six species of cover crops individually, in functional
group combinations (representing oilseeds, grasses, or legumes), or with
all species combined (high diversity treatment). We then investigated how
cover crop treatment affected winter wheat yield, soil biogeochemical
properties, microbial community composition, and ecosystem
multifunctionality. Contrary to our expectations, the high diversity
treatment reduced wheat yield and minimally affected soil properties
relative to the fallow control. We observed the greatest positive impact
on agroecosystem multifunctionality and wheat yield in the oilseed +
legume treatment. Soil pH was mediated by cover crop treatment and
identified as the key factor influencing bacterial diversity and
composition, while active microbial biomass during the preceding cover
crop was the best predictor of subsequent winter wheat yield.