Beneficial insects provide ecosystem services that can improve the sustainability of crop production. Pollinators can increase yield of flowering crops, such as canola and legumes, and predatory insects reduce the size of pest populations. Intensive agricultural practices can affect beneficial insects negatively, leading to reduced ecosystem functioning. The result is an increased dependency on chemical inputs and intense management. Organic farming has the potential to support greater biodiversity and associated ecosystem services in agricultural fields. Flowering habitat enhancements have been shown to increase the abundance and diversity of both pollinators and natural enemies in some contexts. The status of pollinators, in particular bees, is an area of great public interest. Little work on flowering habitat enhancements has been done in the large-scale agricultural systems of the Canadian Prairies. Pollinator research has typically focused on crops that are more strictly dependent on pollination services, and have avoided rotational cropping systems with wind-pollinated crops. Natural enemies also use flowering habitat as an important nutrient supplement and as shelter.
Our research proposes to examine how flowering habitat enhancements on field margins affects two groups of beneficial insect: pollinators and generalist predators in organic cropping systems. We will track the abundance and diversity of these insects across crop rotations and compare organic farms with and without enhancements. We will incorporate details of the surrounding landscape, including the bloom of mass-flowering crops and semi-natural habitat features, which may also affect insect communities. To determine potential negative side effects of introducing flowering habitat enhancements, we will also assess weed abundance near the enhancements. We will measure pollination service to flowering crops and abundance of pest insects to determine changes in ecosystem services resulting from our experimental treatment. We will develop fact sheets and best management practices (BMPs) for effective land management for sustainable crop production. In addition to direct benefits to crop production our work has potential ecological and social benefits, including protection of wild pollinators, a taxon garnering a great deal of public attention. By quantifying the impact of management practices that support biodiversity in agricultural systems, we hope to build resiliency into these systems to protect them from changing conditions and pest outbreaks.
Flower strip beside grain field in southren Manitoba, Aug 2019. (Photo by Michael Killewald)