Choosing annual cover crops in Atlantic Canada

Citation

McKenzie-Gopsill A (2022) Choosing annual cover crops in Atlantic Canada. AAFC Factsheet, Sept 2022.

Plain language summary

Cover crops are being adopted into crop rotations as a way to increase diversity and provide natural benefits including reducing weeds. Recent studies have suggested biomass of cover crop mixtures may be more important than diversity for weed reduction. To investigate productivity and weed suppression of cover crops and mixtures of different cover crops researchers assessed 19 cover crop species and 19 mixtures of two or three cover crops grown over a full season in Atlantic Canada. More diverse cover crop mixtures provided greater productivity and weed suppression. Highly productive species grown individually and diverse mixtures provided the greatest suppression of weeds. Moreover, cover crop mixtures containing highly productive species resulted in the greatest diversity and weed suppression. Similarly, these mixtures provided the greatest year-over-year stability. Our results suggest that the effects of biomass and diversity on cover crop productivity and weed suppression differ by species. This highlights the importance of species selection in deciding which cover crop to use.

Abstract

Cover crops are being adopted into crop rotations as a way to increase diversity and provide natural benefits including reducing weeds. Recent studies have suggested biomass of cover crop mixtures may be more important than diversity for weed reduction. To investigate productivity and weed suppression of cover crops and mixtures of different cover crops researchers assessed 19 cover crop species and 19 mixtures of two or three cover crops grown over a full season in Atlantic Canada. More diverse cover crop mixtures provided greater productivity and weed suppression. Highly productive species grown individually and diverse mixtures provided the greatest suppression of weeds. Moreover, cover crop mixtures containing highly productive species resulted in the greatest diversity and weed suppression. Similarly, these mixtures provided the greatest year-over-year stability. Our results suggest that the effects of biomass and diversity on cover crop productivity and weed suppression differ by species. This highlights the importance of species selection in deciding which cover crop to use.

Publication date

2022-08-03

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