INTERNATIONAL JOURNAL OF PHARMACY & LIFE SCIENCES (Int. J. of Pharm. Life Sci.) Influence of Cobalt on Soybean Growth and Production under Different Levels of Nitrogen

Two field experiments were carried out to evaluate influence of cobalt under different levels of nitro gen on nodules efficiency, growth and yield, minerals composition and chemical characteristics of Soybean plants. The experiments were conducted at Research and Production Station, National Research Centre, El-Nobaria Beheara Governorate, Delta- Egypt, under drip irrigation system during 2 011 and 2012 seasons. The obtained results are summarized in the following: Cobalt significantly increased nitrogenase activity which was parallel and related to the increased no dules numbers, weights and its efficiency especially with both 100 and 75% nitrogen fertilizer. Cobalt gave the highest figures of all growth and y ield parameters of Soybean with 100% N followed by 75% N compared with the untreated plants. Growth and yield parameters of Soybean treated with cobalt and 50% N was not significant while cobalt with 25% N gave the lowest figures. Cobalt increased the efficiency of nitrogen fertili zation, amendment reduce the recommended dose of about by 25% and resulted in superior seeds and oil yields by ab out 20.8% and 17. 4 respectively, with75% N, compared with 100 N without cobalt. Cobalt significantly increased the content of N, P, K, Mn and Zn as well as chemical contents especial ly with 100% and 75% nitrogen levels. Finally, the addition of Cobalt to the soil, save 7 5% nitrogen and could be reduced.