He worked in plant breeding programs in Africa. After returning to England, he was employed by the Department of Botany of Southampton University from 1967 to 1996. Initially, he was a Lecturer in Genetics, while achieving the status of Reader in Biology in 1990. Southampton University honoured Smartt by awarding him a Doctor of Science in 1989 for his work on the genetics and evolution of crop plants. Smartt authored two books on grain legumes, edited a major volume on groundnuts, and was invited to co-edit a second edition of the important Evolution of Crop Plants with the late Professor Norman Simmonds.
On fish
Smartt, J.. Goldfish Varieties and Genetics: Handbook for Breeders. John Wiley & Sons. Smartt, J.. A possible genetic basis for species replacement: preliminary results of interspecific hybridisation between native crucian carp Carassius carassius and introduced goldfish Carassius auratus. Aquatic Invasions 2:59-62. Smartt, J. & Bundell, J. H.. Goldfish breeding and genetics. TFH.
On the evolution of crop plants and grain legumes
Books
Nwokolo, E. & Smartt, J... Food and feed from legumes and oilseeds. Chapman & Hall, London. Simmonds, N. W. & Smartt, J.. Principles of crop improvement, 2nd edn. Blackwell Science, Oxford. Smartt, J. & Simmonds, N. W.. Evolution of crop plants, 2nd edn. Longman Scientific & Technical. Smartt, J.. The groundnut crop: a scientific basis for improvement. Chapman & Hall Ltd. Smartt, J.. Grain legumes: evolution and genetic resources. Cambridge University Press. Smartt, J.. Tropical pulses. Longman Group Limited. Smartt, J., Cross-compatibility relationships between the cultivated peanut Arachis hypogaea L. and other species of the genus Arachis. PhD thesis, North Carolina State University.
Scientific articles
Erskine, W., Smartt, J. & Muehlbauer, F. J.. Mimicry of lentil and the domestication of common vetch and grass pea. Economic Botany 48:326-332. Harder, D. K. & Smartt, J.. Further evidence on the origin of the cultivated winged bean, Psophocarpus tetragonolobus DC.: Chromosome numbers and the presence of a host-specific fungus. Economic Botany 46:187-191. Smartt, J.. Evolution of grain legumes. VI. The future—the exploitation of evolutionary knowledge. Experimental Agriculture 22:39–58. Smartt, J.. Evolution of grain legumes. V. The oilseeds. Experimental Agriculture 21:305–319. Smartt, J.. Evolution of grain legumes. IV. Pulses in the genus Phaseolus. Experimental Agriculture 21:193–207. Smartt, J.. Evolution of grain legumes. III. Pulses in the genus Vigna. Experimental Agriculture 21:87–100. Smartt, J.. Evolution of grain legumes. II. Old and New World pulses of lesser economic importance. Experimental Agriculture 21:1–18. Smartt, J.. Evolution of grain legumes I. Mediterranean pulses. Experimental Agriculture 20:275–296. Smartt, J.. Some observations on the origin and evolution of the winged bean. Euphytica 29:121-123.