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Department of Plant Agriculture


Plant Agriculture


Faculty & Research Scientists
E. Ann Clark Associate Professor (retired)
E. Ann Clark

E. Ann Clark,
Associate Professor


B.S. Biological Sciences, University of California, Davis;
M.S. Agronomy, University of California, Davis;
Ph.D. Crop Production and Physiology, Iowa State University



Email: eaclark@uoguelph.ca

Pasture and grazing management, organic farming, GMOs

Research Interests:

Dairy cows
Dr. Clark was an Associate Professor in Plant Agriculture at the University of Guelph, with specific interests in organic and pasture production systems, and in risk assessment in genetically modified crops. She taugh numerous undergraduate courses, directs the Guelph Centre for Urban Organic Farming, and co-coordinates the B.Sc.(Agr) Organic Agriculture major. In addition to her teaching and research responsibilities, she was also a frequent invited speaker at scholarly and producer conferences.

Archival information on Dr. Clark's work in Plant Agriculture:

Selected Publications:

Clark, E. Ann. 2009.  Ch. 5 (invited). Forages in Organic Crop-Livestock Systems.  pp. 85-112.  In: C. Francis (ed) Organic Farming: The Ecological System.  Agronomy Monograph 54.  American Society of Agronomy Inc., Madison, WI.

Clark, E. Ann. and J. Sumner.  2009 (invited).  Ch. 7. Ontario, Canada.  Lessons in Sustainability from Organic Farmers.  pp. 133-164.  In: S.R. Gliessman and M. Rosemeyer (eds) The Conversion to Sustainable Agriculture.  Principles, Processes, and Practices.  CRC Press.  Taylor & Francis Group, Boca Raton.

Clark, E. Ann. 2007 (invited). GM crops are uncontainable: so what? pp. 139-152 In: R.H. Gulden and C.J. Swanton (eds) the First Decade of Herbicide-resistant Crops in Canada. Topics in Canadian Weed Science Vol. 4. Sainte Anne de Bellevue, Quebec: Canadian Weed Science Society

Clark, E.A. (2006). Environmental risks of genetic engineering. Euphytica 148:47-60.

Papadopoulos, Y.A., D.B. McKenzie, K.B. McRae, E.A. Clark, and E. Charmley. (2005). Evaluating the performance of alfalfa cultivars in rotationally grazed pastures. Can. J. Plant Sci. 85:147-150.

Clark, E.A. (2004). Benefits of re-integrating livestock and forages in crop production systems. J. of Crop Improvement 12(1/2):405-436.

Clark, E.A. (2004). GM Crops Are Not Containable. pp. 91-108 In: B. Breckling.and R. Verhoeven (eds) Risk Hazard Damage. Specification of Criteria to Assess Environmental Impact of Genetically Modified Organisms. Naturschutz und Biologische Vielfalt. Ecological Society of Germany, Austria and Switzerland. Hannover, Germany 8-9 December 2003.