Prof. Deen is specialized in crop sciences. Since 1997, he is associated with the Department of Plant Agriculture at the University of Guelph. In addition, Prof. Deen operates a broiler and beef farm in Wellington County, Ontario, Canada. The productive and sustainable agroecosystems are the main focus of his research. His areas of research interest are:
- Bioenergy crop systems
- Crop rotation
- Carbon and nutrient cycling
