The role of cover crops as a floral resource for native bee conservation in agroecosystems

Project Overview

Project Type: Graduate Student
Funds awarded in 2012: $14,929.00
Projected End Date: 12/31/2014
Grant Recipient: Penn State University
Region: Northeast
State: Pennsylvania
Graduate Student:
Faculty Advisor:
Mary Barbercheck
PSU Dept. of Entomology

Annual Reports

Information Products


  • Agronomic: canola, grass (misc. perennial), hay
  • Vegetables: peas (culinary)
  • Animals: bees


  • Animal Production: feed/forage
  • Crop Production: cover crops, crop rotation
  • Education and Training: extension, networking, on-farm/ranch research
  • Natural Resources/Environment: biodiversity, habitat enhancement, wildlife
  • Pest Management: field monitoring/scouting, weather monitoring, weed ecology
  • Production Systems: organic agriculture
  • Soil Management: green manures
  • Sustainable Communities: sustainability measures

    Proposal abstract:

    Conservation of natural processes such as pollination, pest control, and nutrient cycling are essential to maintaining a healthy agroecosystem. The incorporation of cover crops into annual crop rotations is one practice that is used in the Northeast U.S. to manage soil fertility, weed suppression, and erosion control. Additionally, cover crops that have a flowering stage have the potential to support beneficial insect communities, such as native bees. Because of the current decline facing managed honeybee colonies, the conservation of native bee communities is critical to maintaining ‘free’ pollination services. However, native bees are negatively affected by agricultural intensification and are in decline across North America. This project will assess the potential of flowering cover crop species to act as a conservation resource for native bee communities, in addition to providing benefits to soil fertility and agricultural production. Six flowering cover crop species will be evaluated to determine their various blooming time frames as well as the different native bee communities that use their resources. Each cover crop will be planted with two planting dates and considered for their potential use in a variety of standard crop rotations in the Northeastern US. Project results will be distributed to the public, particularly farmers and land managers, through a series of extension publications and field days highlighting the role of cover crops in native pollinator conservation. The effectiveness of these publications in changing knowledge and intention for behavior change will be evaluated.

    Project objectives from proposal:

    OBJECTIVE 1: To identify (a) the blooming time frames of six common Northeast U.S. flowering cover crop plant species, and (b) the effect of cover crop planting and termination date on peak bloom.

    Expected Outcome: We predict that cover crops that are planted earlier in the fall will reach peak bloom before those with a later planting date, and those with later termination dates will have increased likelihood for each cover crop to reach its peak bloom during that rotation.

    OBJECTIVE 2: To identify (a) the native bee species that visit cover crop flowers for pollen and nectar resources, (b) when those bee species are most abundant in the environment and how that relates to cover crop bloom, and (c) what potential pollinator benefits may be lost through early termination of cover crops in standard crop rotations.

    Expected Outcome: We predict that variations in cover crop blooming period will attract unique communities of native bees during the spring and fall growing seasons and at different parts of each season (e.g., early versus late spring). Additionally, we predict that early termination of cover crops in the spring prior to peak bloom will reduce the potential benefit of the floral resources to local native bee communities.

    OBJECTIVE 3: (a) To participate in a series of public outreach activities highlighting the benefits of flowering cover crops for conservation of native bee species. (b) To create and distribute an extension publication that illustrates the results of this project and assists growers in determining the optimal species for use in their rotation.

    Expected Outcome: To increase public awareness of the importance of native bees to crop and native plant pollination and to help recruit more Northeast growers to incorporate flowering cover crops into their crop rotations.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.