Don Smith is the James McGill Professor at McGrill University.

Dr Smith's research interests are in the area of crop eco-physiology. They can be broken down into several specific areas of activity. One of these is the use of signal compounds to improve legume nitrogen fixation under environmental conditions inhibitory to symbiosis development. This work has led to a number of publications, patents, and the establishment of a spin-off company. A second area is the use of plant growth promoting rhizobacteria (PGPR), and signal compound produced by them, to increase the growth and yield many crops. This led to the isolation of several new PGPR strains and the isolation of a material, produced by a PGPR, that causes direct stimulation of plant growth. A third area of research is the use of the signal compounds produced by rhizobia during the establishment of the rhizobia-legume symbiosis to directly promote plant growth. Fourth, research is methods to increase the sequestration of CO2 from the atmosphere into crop plants, including the use of biochar, for ultimate sequestration into soil, or for use in bioproducts. This is linked to the utilization of crop plants in greenhouse gas management, including use of lignocellulosics produced by crop plants as biofuel feedstocks.