| Abstract | Two field trails were conducted during the two successive seasons 20072008 on maize plants at the experimental farm of Sakha Agric. Res. Station, Kafr El- Sheikh Governorate, Egypt. The aim of this study was to investigate the influence of maize grain treated with Azotobacter chroococcum and Bacillus megatherium and their combinations with NPK under three N-levels; 80, 100, and 120 kg N/fad for N1, N2, and N3 to increase yield, NPK uptake by maize plants and the availability of NPK in the soil. The experiments were conducted in split plot design, with three replicates. The observed results can be summarized as follows: • The yield and components of maize, NPK uptake and the availability of NPK in the studied soil were affected significantly by biofertilizer treatments and N-levels. • The maximum values of available N were obtained by the application of Azotobacter chroococcum and Bacillus magetherium with NPK under N3 treatment. The maximum values of available P were recoded by the application of Bacillus megatherium with NPK under N3 treatment. • Combination of A.chroococcum, B.megatherium, and NPK fertilizers under N3 significantly increased grain yield (20.9 and 17.9%), straw yield (16.8 and 20.6%), 100-grain weight (9.9 and 13.3%), ear weight (21.0 and 18.0) and N, P, and K uptake by maize grain [(35.1 and 31.3%), (21.2 and 26.9%) and (18.1 and 31.1%)] over the control for N, P, and K, respectively, in 2007 and 2008 seasons. While shelling percentage did not significantly affected by different treatments. The application of these results should help in reducing environmental pollution. |