Leopold Center for Sustainable Agriculture

Research Results

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Summaries

Easy-to-read summaries are available for these recently completed projects funded by Leopold Center competitive grants.

Scientific Journals

Leopold Center-supported projects have produced these papers published in peer-reviewed journals. Check at a research library or the journal’s website for an abstract or full report.

  • Lammers, P.J.; M.D. Kenealy, J.B. Kliebenstein, J.D. Harmon, M.J. Helmers and M.S. Honeyman (2012). Energy use in pig production: An examination of current Iowa systems, Journal of Animal Science 90:1056-1068. http://dx.doi.org/10.2527/jas.2010-3782

This was part of a competitive grant, “Energy use and nutrient cycling in pig production systems.” Lammers calculated direct and indirect energy flows into and through a conventional confinement system with mechanical ventilation and liquid manure handling, and one that uses bedded hoop barns for grow-finish pigs and gestating sows.

  • McCann, N. and F. Montabon, Strategies for accessing volume markets in the beef industry: A review of three case studies, Journal of Agriculture and Food Systems Community Development 2(2):37-49. http://dx.doi.org/10.5304/jafscd.2012.022.014

This research project was conducted by former Leopold Center graduate research assistant Nick McCann, who examined three cooperative models for specialty beef producers to access the market in profitable volumes.

  • Gomez, R., M. Liebman, D. Sundberg and C. Chase (2012). Comparison of crop management strategies involving crop genotype and weed management practices in conventional and more diverse cropping systems, Renewable Agriculture and  Food Systems (accepted 14 March 2012), doi:10.1017/S1742170512000142

This ongoing research has been supported by several competitive grants from the Leopold Center. It compares a two-year corn-soybean rotation with longer, more diverse rotations that include forage legumes and small grains in addition to corn and soybean. During 2003-2011, corn yields were 4 percent higher and soybean yields were 9 percent higher in the three- and four-year rotations than in the two-year rotation. Increased diversity allowed large reductions in chemical inputs: nitrogen fertilizer use was 89 percent lower and herbicide use was 88 percent lower in the more diverse systems. Net returns to land and labor did not differ significantly among rotation systems.

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