Lee’s research responds to the decline in on-farm biodiversity by evaluating the effects of cover crops, especially red clover and winter wheat, on crop yield and biodiversity levels. The findings provide practical guidance on selecting effective cover crops and emphasize the importance of balancing immediate economic benefits with long-term sustainability for farmers in Southwestern Ontario.
Agro-ecosystems in Eastern and Central Canada are experiencing a significant decline in biodiversity, driven by simplified crop rotations, loss of perennial forage, and shrinking habitats. These factors make agro-ecosystems more vulnerable to climate change and environmental stress, resulting in reduced soil health, increased reliance on fertilizers, and heightened water pollution. Diversification practices like crop rotation, cover crops, and farm landscaping can help improve soil health, nutrient cycling, water filtration, and overall productivity. However, cover crop adoption, particularly in corn and soybean rotations, has been limited due to a lack of research tailored to farmers’ needs. This research aims to enhance biodiversity in Southwestern Ontario’s agricultural systems by identifying practical strategies to boost cover crop adoption, provide reliable benefits to producers, and offer flexibility, ultimately improving both ecological and economic resilience in the face of climate change.
Dr. Elizabeth Lee and her team aimed to close critical knowledge gaps about cover crop use and its role in enhancing agricultural landscapes. Through long-term, multi-site trials, the project generated evidence to support the wider adoption of cover crops, focusing on making their benefits more immediate and reliable. The research highlighted cover crops’ economic and environmental benefits, such as improving soil health, boosting biodiversity, and increasing drought resilience. Lee’s team also aimed to develop dual-purpose cover crops that would not only enhance soil health but also serve as pollinator habitats, contributing to the restoration of native Ontario prairie ecosystems.
The project revealed several important findings about cover crop use, particularly the effectiveness of multi-species mixtures, the role of red clover, and its interaction with nitrogen fertilizer. A key takeaway was that no single cover crop species can provide all potential benefits, and species selection should be based on functional complementarity rather than simply increasing species numbers. Red clover emerged as a highly effective cover crop, outperforming other varieties like alsike and crimson clover in frost-seeded trials. It provided nitrogen storage and improved soil health. Additionally, multi-species mixtures did not outperform monocultures in terms of biomass production. While cover crops did not increase corn yields with adequate nitrogen supply, they showed positive effects in nitrogen-limited scenarios. The research emphasized that environmental conditions significantly affect cover crop success and that both short- and long-term impacts must be considered when evaluating their use. Overall, the project reinforced the value of red clover and provided practical guidance for selecting cover crops that align with specific farm goals and conditions.
The findings provide a valuable dataset to inform provincial strategies for using cover crop species in pollinator habitat creation across Southwestern Ontario. These insights offer guidance for improving agricultural sustainability and soil health management, especially in temperate regions. The project highlights that well-managed single species, like red clover, may sometimes be more beneficial than multi-species mixtures. It also underscores the need to balance short-term economic gains with long-term soil health benefits and identifies management practices, such as twin-row winter wheat spacing, that can enhance cover crop establishment. This research by Lee’s team is directly applicable to farmers, advisors, and policymakers, promoting increased cover crop adoption and success while emphasizing the need for context-specific recommendations.
Chapagain, T., Lee, E. A., & Raizada, M. N. (2020). The Potential of Multi-Species Mixtures to Diversify Cover Crop Benefits. Sustainability, 12(5), 2058. https://doi.org/10.3390/su12052058
Hilker, B. (n.d.). Examinations of red clover (Trifolium pratense L.) as a cover crop.
Stewart, M. D. (n.d.). Nitrogen Fertilizer Cover Crop Responses Seeded After Wheat and Effect on Grain Corn Yield in the Short-Term.
