David Chalmers Crawford, son of Alexander Crawford, qualified as Master of Arts (MA, 1901) and Bachelor of Agricultural Science (BSc Agr, 1906) at the University of Aberdeen, Scotland, and was associated with the Aberdeen Agricultural College. In August 1909 he came to the Cape Colony to take up an appointment as lecturer in agricultural chemistry at the School of Agriculture, Elsenburg, where he succeeded George N. Blackshaw*. By 1912 grain fertiliser experiments were being conducted at the school under his direction and he continued participating in crop and pasture investigations there until 1926. In that year the school amalgamated with the Faculty of Agriculture at the University of Stellenbosch to form the Stellenbosch-Elsenburg College of Agriculture.
Crawford became a member of the South African Association for the advancement of Science in 1909. A few years later he was the co-author, with viticulturalist Prof. A.I. Perold*, of a paper on "Some preliminary investigations into the chemical composition of certain vineyard soils in the Montague and Robertson Districts". The paper was read at the annual congress of the association in 1914 and published in its Report for that year (pp. 337-349). Crawford was still active in agricultural chemistry in 1942, when he wrote The chemical composition of some South African cereals and their milling products (Government Printer, 1942).
During World War I (1914-1918) Crawford served as a driver in the South African Service Corps in East Africa from August 1916 to March 1919, with the final rank of sergeant.