Leopold Center for Sustainable Agriculture

Long-Term Agroecological Research


This experiment at the ISU Neely-Kinyon Research and Demonstration Farm near Greenfield, Iowa was set up in 1998, the capstone of the Organic Ag program at Iowa State University. It is one of the longest running comparisons of organic and conventional crops in the country. The Leopold Center has supported the LTAR project since it began. Research continues with competitive grant funding from the Leopold Center and other sources.

The goals of the Long-Term Agroecological Research Team:

  • To examine the agronomic, economic and environmental performance of conventional and organic systems, using certified organic production practices, including:
    • Soil and water quality
    • Energy use
    • Yields and economic returns
    • Weed management

LTAR is a randomized, replicated comparison of the following rotations:

  • Conventional corn-soybean (2 year)
  • Organic corn-soybean-oats/alfalfa (3 year)
  • Organic corn-soybean-oats/alfalfa-alfalfa (4 year)
  • Organic soybean-wheat/red clover (2 year)

This publication outlines the impact of Leopold Center support for this research.

Research team resources

Related grant projects

Links we like

Research reports and other information can be found on the ISU Organic Agriculture website.

For more information, contact Kathleen Delate, ISU Horticulture/Agronomy, (515) 294-7069.