Leopold Center for Sustainable Agriculture

Completed Competitive Grant

Establishment of a field school for weed ecology and management

Project ID: E2004-06

Abstract

Multiyear field experiments using three crop rotations, two of which were low-external-input (LEI) systems, showed that cropping systems can be designed to achieve large reductions in agrichemical use while providing effective weed control and high yields and profits.

Key Question: Can diversified, low-external-input (LEI) cropping systems produce yields and profits that match or exceed those obtained from conventional systems?

Findings: These results show that diversified LEI systems can produce yields and profits that match or exceed those obtained from conventionally managed corn-soybean systems. Additionally, we learned that ecological processes such as weed seed consumption by rodents and insects can promote effective weed control in LEI systems, while allowing substantial reductions in herbicide use. Weed seed losses to rodents and insects can be enhanced by delaying tillage operations to leave seeds on the soil surface for as long as possible.

Lead investigator: Matt Liebman, ISU Agronomy, et al

Year of grant completion: 2009

This competitive grant project was part of the Leopold Center's Ecology Initiative.

Topics: Multi-year rotations, low-external input, Economic and environmental impacts, Soils and agronomy, Weed control alternatives (not GMOs)