Predator-prey interactions in a high residue, reduced tillage agroecosystem

Project Overview

Project Type: Graduate Student
Funds awarded in 2012: $14,234.00
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


  • Agronomic: corn, soybeans, wheat


  • Crop Production: conservation tillage, cover crops, crop rotation
  • Natural Resources/Environment: biodiversity
  • Pest Management: biological control
  • Production Systems: organic agriculture

    Proposal abstract:

    Many studies have noted the significance of reduced tillage and increased crop residue to the generalist predator community in agroecosystems. However, many of these studies have assumed their benefit to levels of predation and biological control without actually measuring them (Letourneau and Bothwell 2008). As such, we will monitor both the early-season pests and predator communities in an organic reduced tillage system, in which cash crops are no-till planted at three different dates into a heavy mulch layer created by managing a winter cover crop with a roller-crimper. Additionally, we will conduct predation assays to help estimate potential levels of predation. By evaluating both pest and beneficial arthropod communities, and conducting predation assays, we can better understand how reducing tillage in a cash crop – cover crop rotation may benefit organic growers in managing pests, and provide information to support grower decision-making about whether adoption of these practices for their tangible benefits to on-farm sustainability will be advantageous to them.

    Project objectives from proposal:

    Objective 1: Characterize the beneficial and early-season pest arthropod community in a high cover crop residue environment associated with a reduced-tillage organic feed grain rotation.

    The increased habitat complexity associated with cover cropping and reduced tillage can be attractive to a variety of arthropods. It is therefore important to understand what arthropods are in the field to know how they affect pest and beneficial arthropod communities.

    Objective 2: Determine the effect of three cover crop management and cash crop planting dates on the arthropods in a reduced-tillage organic feed grain rotation.

    The presence and life stage of pest and beneficial arthropods are affected by several environmental factors, including amount and condition of cover crop residue, weather, and host availability and life stage. Therefore, timing of cover crop management and cash crop planting will affect potential crop damage by early season insect pests. By characterizing the ground-dwelling arthropod community, we can determine if predators are present at the same time as potential early-season pests, and which cover crop management and planting dates can maximize the level of predation on pest populations.

    Objective 3: Determine the relationship between the arthropod community and early season crop damage and plant population in a reduced-tillage organic feed grain rotation.

    The presence of predators at the same time as pests may only be beneficial if the predators are contributing to control of the pests. By measuring crop damage in relation to pest and predator populations, we will determine what, if any, effect the predator community may have on preventing crop damage.

    Objective 4: Determine the potential impact of generalist insect predators on populations of early-season pests associated with a reduced-tillage organic feed grain rotation.

    Knowing that the predators and pests are present at the same time will contribute to the knowledge that these predators are at least available to prey upon insect pests. Laboratory and in-field predation assays will help estimate the potential for predators to actually reduce pest populations.

    Objective 5: Provide opportunities for the exchange of information with organic growers about this production system and its effects on beneficial and pest arthropods.

    By working with organic growers to disseminate the information about this project and evaluate their perceptions, we can determine benefits and challenges to grower adoption of organic reduced tillage crop production, and determine additional information needed to gain grower acceptance and adoption.

    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.