Gideon Johannes ('Mielie') Bosman, agriculturalist, was the son of Gysbert Wilhelm Gustav ('Willie') Bosman and his wife Jacoba ('Kobie') Kleyn. He matriculated at the Boys' High School, Stellenbosch, in 1907 and continued his studies at the Iowa State University in the United States, which awarded him the degree Bachelor of Science in Agriculture (BSA) in 1912. His studies there included a dissertation on Plant food in its relation to agriculture (Iowa State University, 1912). Upon his return to South Africa he was appointed as agriculturalist at the Grootfontein School of Agriculture near Middelburg, Cape Province, and wrote two articles for publication in the Agricultural Journal (Union of South Africa): "Agricultural education in the USA" and "Brief notes on modern silo construction" (both in 1913, Vol. 5).
Ten years later Bosman collaborated with H.D. Leppan in writing a comprehensive treatise on Field crops in South Africa (Johannesburg: CNA, 1923, 358 pp.) Soon thereafter he wrote Suid-Afrikaanse gesaaides (South African field crops; Bloemfontein, 1925, 160 pp.) a handbook for farmers, agricultural students and rural teachers. He also collaborated with S.H. Skaife* to produce a book on Maize (Cape Town, 1927, 120 pp.)
In 1926 Bosman succeeded E. Parish* as Head of the Glen College of Agriculture near Bloemfontein, a post he held until 1929. In 1920 he married Carolina Francina de Waal, with whom he had two sons.