Cobalt application is important for maintaining and improving plants properties. Two field experiments were conducted on a sandy loam soil during the two consecutive winter seasons of 2020/2021 and 2021/2022 to examine the influence of cobalt and /or various nitrogen sources on broad bean (Vicia faba L.). The first was designed to investigate the influence of nitrogen source (without cobalt), and the second was to investigate the influence of cobalt + nitrogen sources (with cobalt) on broad bean plants. Results showed that cobalt applying to the soil increased nitrogenase enzyme activity which was parallel and associated to the increase nodules formation rate of broad bean with urea, ammonium nitrate and ammonium sulphate with compared to the control. Cobalt significantly enhanced growth, seed yield as well as nutritional studied and chemical constituents with various nitrogen sources. Cobalt application with ammonium sulphate resulted maximum values followed by ammonium nitrate while urea gave the lowest ones. Cobalt increased seed yield of broad bean by 13.5% with urea, 21.4% with ammonium nitrate and 24.0% with ammonium sulphate while 7.85% with control treatment. Thus, application of cobalt improved the nitrogen fertilizer use efficiency in newly reclaimed soil with broad bean plants.