Leopold Center for Sustainable Agriculture

Completed Competitive Grant

Impacts of conventional and diversified rotation systems on crop yields, profitability, soil functions and environmental quality

Project ID: E2010-02

Abstract

Comparisons were made among contrasting cropping systems within a long-term, large-scale field experiment in Boone County, Iowa. Combining crop diversity with lower herbicide inputs and non-transgenic crops was effective in reducing requirements for nitrogen fertilizer; maintaining or improving weed suppression, grain yields, and profi ts; and increasing several soil quality indicators.

Key Question: How do cropping system diversity and contrasting technology packages of crop genetics and herbicide inputs affect agrichemical use, crop performance, weeds, soil quality and function and profitability?

Findings: Comparisons were made among contrasting cropping systems within a long-term, large-scale field experiment in Boone County, Iowa. Combining crop diversity with lower herbicide inputs and non-transgenic crops was effective in reducing requirements for nitrogen fertilizer; maintaining or improving weed suppression, grain yields, and profits; and increasing several soil quality indicators.

Lead investigator: Matt Liebman, ISU Agronomy

Co-Investigator(s):

Craig Chase, Leopold Center, Tom Sauer, USDA-ARS, Mark Tomer, USDA-ARS, Michelle Wander, University of Illinois, Urbana-Champaign

Year of grant completion: 2013

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

Topics: Multi-year rotations, low-external input, Soils and agronomy