Do diverse cover crop mixtures perform better than monocultures? A systematic review

Abstract

Multi-species cover crop mixtures have been increasing in popularity. It has been hypothesized these mixtures produce more biomass, suppress more weeds, scavenge more N, conserve more soil water, stimulate more soil biology, promote higher yields of subsequent crops, and have higher production stability than the best of their monoculture counterparts. This systematic review synthesizes a growing body of cover crop mixture research to assess, for these metrics, whether cover crop mixtures can perform better than their constituent species when planted alone. Searching three databases, we identified 27 studies which compared cover crop mixtures (containing at least three species) to all their constituent species. The studies contained 119 sampled cover crop plantings that met our eligibility criteria. From these, we extracted 243 full comparisons of the bestperforming mixture and best-performing monoculture for the selected metrics. In 88% of these comparisons, the monoculture and mixture performed comparably. In 10% of the comparisons, the monoculture did better, and in 2% of comparisons the mixture performed better. Overall, there are few published studies documenting the superiority of cover crop mixtures over monocultures for our selected metrics. Abbreviations: CC, cover crop; CV, coefficient of variation; LER, land equivalent ratio; RYT, relative yield total. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Crop Diversification for Improved Weed Management: A Review

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Regenerative agriculture and integrative permaculture for sustainable and technology driven global food production and security

“…Fornara & Tilman (2009) described the improvements in soil structure and health from increased soil organic matter, soil microorganisms and biological activities from increased plant diversity during decomposition. Then there is the decreased nutrient loss and increased soil water retention from increased plant diversity which increases crop productivity (Florence & McGuire, 2020) while simultaneously decreasing environmental contamination. Both diverse agronomic managements and cropping systems are key components of an integrated pest management system.…”

Functional Diversity of Soil Nematodes in Relation to the Impact of Agriculture—A Review

“…The stability and beneficial ecosystem functions and services (e.g., regulation of weeds, pests or pathogens) of intensively managed agrosystems can be enhanced by increasing plant diversity through cover plants or associated crops. Increasing the cover crop species diversity is expected to enhance plant productivity through increased resource use efficiency [110]. Multispecies cropping agrosystems perform multiple functions and services other than crop production, increasing soil OM and C sequestration, regulating soil moisture, suppressing weeds, pathogens and pests, retaining N, sustaining higher soil biodiversity, etc.…”