Sam Wortman


·Wortman Research

Sam Wortman

Assistant Professor

B.A., Biology and Environmental Studies, University of St. Thomas, 2007

M.S., Agronomy, University of Nebraska–Lincoln, 2009

Ph.D., Agronomy, University of Nebraska–Lincoln, 2012

Area of Focus

  • Environmental Horticulture

Research Interests

  • Interactions between plants and the environment
  • Local, urban, and organic fruit and vegetable production
  • Novel management tactics for improved sustainability of specialty crop farms

Courses Taught


  • F. Forcella, D. Humburg, S. Wortman and S.A. Clay. 2017. Air-propelled abrasive grit can damage the perennial weed, quackgrass. Canadian Journal of Plant Science.
  • R.F. Graham, S.E. Wortman and C.M. Pittelkow. 2017. Comparison of organic and integrated nutrient management strategies for reducing soil N2O emissions. Sustainability 9 (4), 510 2.
  • Taylor J.R., S.T. Lovell, S.E. Wortman and M. Chan. 2017. Ecosystem services and tradeoffs in the home food gardens of African American, Chinese-origin and Mexican-origin households in Chicago, IL. Renewable Agriculture and Food Systems 32 (1), 69-86 5.
  • A.A. Holmes, A.A. Thompson and S.E. Wortman. 2017. Species-Specific Contributions to Productivity and Weed Suppression in Cover Crop Mixtures. Agronomy Journal 109 (6), 2808-2819.
  • S.E. Wortman, A.A. Holmes, E. Miernicki, K. Knoche and C.M. Pittelkow. 2017. First-Season Crop Yield Response to Organic Soil Amendments: A Meta-Analysis. Agronomy Journal 109 (4), 1210-1217.
  • Wortman, S. E. 2016. Weedy fallow as an alternative strategy for reducing nitrogen loss from annual cropping systems. Agronomy for Sustainable Development: DOI: 10.1007/s13593-016-0397-3.
  • Wortman, S. E., M. S. Douglass, and J. Kindhart. 2016. Cultivar, growing media, and fertilizer source influence strawberry yield in a vertical, hydroponic, high tunnel system. HortTechnology 26:466-473.
  • Wortman, S. E., I. Kadoma, and M. D. Crandall. 2016. Biodegradable plastic and fabric mulch performance in field and high tunnel cucumber production. HortTechnology 26:148-155.
  • Wortman, S. E. 2015. Air-propelled abrasive grits reduce weed abundance and increase yields in organic vegetable production. Crop Protection 77:157-162.
  • Wortman, S. E. 2015. Crop physiological response to nutrient solution electrical conductivity and pH in an ebb-and-flow hydroponic system. Scientia Horticulturae 194:34-42.
  • Wortman, S. E., I. Kadoma, and M. D. Crandall. 2015. Assessing the potential for spunbond, nonwoven biodegradable fabric as mulches for tomato and pepper crops. Scientia Horticulturae 193:209-217.
  • Wortman, S. E., and J. O. Dawson. 2015. Nitrogenase activity and nodule biomass of cowpea (Vigna unguiculata L. Walp.) decrease in cover crop mixtures. Communications in Soil Science and Plant Analysis 46:1443-1457. 
  • Wagstaff, R., and S. E. Wortman. 2015. Crop physiological response across the Chicago metropolitan region: Developing recommendations for urban and peri-urban farmers in the North Central US. Renewable Agriculture and Food Systems 30:8-14. (Special Issue on Innovations and Trends in Sustainable Urban Agriculture)
  • Wortman, S. E., J. J. Schmidt, and J. L. Lindquist. 2014. Weed suppressive potential of sudangrass is driven by interactions of root exudates and decomposing shoot residue. Crop Management 13: DOI 10.2134/CM-2013-0037-RS.
  • Wortman, S. E. 2014. Integrating weed and vegetable crop management with multifunctional air-propelled abrasive grits. Weed Technology 28:243-252.
  • Wortman, S. E., R. A. Drijber, C. A. Francis, and J. L. Lindquist. 2013. Arable weeds, cover crops, and tillage drive soil microbial community composition in organic cropping systems. Applied Soil Ecology 72:232-241.
  • Wortman, S. E. and S. T. Lovell. 2013. Environmental challenges threatening the growth of urban agriculture in the United States. Journal of Environmental Quality 42:1283-1294.
  • Wortman, S. E., C. A. Francis, T. D. Galusha, C. Hoagland, J. Van Wart, P. S. Baenziger, T. Hoegemeyer, and M. Johnson. 2013. Evaluating cultivars for organic farming: Maize, soybean, and wheat genotype by system interactions in Eastern Nebraska. Agroecology and Sustainable Food Systems 37:915-932.
  • Wortman, S. E., C. A. Francis, M. A. Bernards, E. E. Blankenship, and J. L. Lindquist. 2013. Mechanical termination of diverse cover crop mixtures for improved weed suppression in organic cropping systems. Weed Science 61:162-170.
  • Schutte, B. J., S. E. Wortman, J. L. Lindquist and A. S. Davis. 2013. Maternal environment effects on phenolic defenses in Abutilon theophrasti seeds. American Journal of Plant Sciences 4:1127-1133.
  • Wortman, S. E., A. S. Davis, B. J. Schutte, J. L. Lindquist, J. Cardina, J. Felix, C. L. Sprague, J. A. Dille, A.H.M. Ramirez, G. Reicks, and S. A. Clay. 2012. Local conditions, not regional gradients, drive demographic variation of Ambrosia trifida and Helianthus annuus across Northern US Maize Belt. Weed Science 60:440-450.
  • Wortman, S. E., C. A. Francis, M. Bernards, R. Drijber, and J. L. Lindquist. 2012. Optimizing cover crop benefits with diverse mixtures and an alternative termination method. Agronomy Journal 104:1425-1435.
  • Wortman, S. E., C. A. Francis, and J. L. Lindquist. 2012. Cover crop mixtures for the Western Corn Belt: Opportunities for increased productivity and stability. Agronomy Journal 104:699-705.
  • Wortman, S. E., T. Galusha, S. C. Mason, and C. A. Francis. 2012. Soil fertility and crop yields in long-term organic and conventional cropping systems in Eastern Nebraska. Renewable Agriculture and Food Systems 27:200-216.
  • Wortman, S. E., A. S. Davis, B. Schutte., and J. L. Lindquist. 2011. Integrating management of soil nitrogen and weeds. Weed Science 59:162-170. 
  • Wortman, S. E., J. L. Lindquist, M. Haar, and C. A. Francis. 2010. Increased weed diversity, density and aboveground biomass in long-term organic crop rotations. Renewable Agriculture and Food Systems 25:281-295.