Sam Wortman


·Wortman Research

Sam Wortman

Assistant Professor

Area of Expertise: Turf, Landscape, and Horticulture Systems

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.