Karim was born on 1 February 1920 in Kalma village in Lohajang Upazila, Munshiganj District, Bengal Presidency, British India.
[1] In 1945, he started his PhD in agricultural chemistry at Imperial College London and finished in 1948.
[1] He was appointed a gazetted officer in the chemical standardization laboratory of the Bengal Ministry of Food and Drug.
[1] In 1949, Karim joined the Department of Soil Science in University of Dhaka as senior Lecturer.
[1] In 1961, Karim returned from the United States and was appointed head of Soil Science Department of the University of Dhaka.