Effects of non-symbiotic nitrogen-fixing bacteria under different levels of nitrogen on the growth rate of wheat.

This study was carried out to investigate the effect of inoculation with Cyanobacteria, Azotobacter, and Azospirillum individually or in combination with different mineral-N levels on the growth of wheat plants. A pot experiment was conducted during two successive seasons (2021 and 2022) in the Department of Microbiology, Faculty of Agriculture, Minia University. Results revealed that inoculation with any of the used microorganisms generally encouraged the growth of wheat plants. Also, the treatment with 75 % N + any of the used microorganisms gained the highest plant hight, fresh and dry weight of the plant, highest total N, P, and K contents of the plants. The obtained results indicated that no significant differences in the studied measurements were observed between the treatment with 75 % N + any of the used microorganisms and the application of 100% mineral N. Such results may suggest that inoculation of wheat plants with cyanobacteria or diazotrophic bacteria may preserve nearly 25% of the mineral nitrogen required for wheat production. The most successful inoculum for wheat development was determined to be the mixture of the studied microorganisms, Moreover, all of the microorganisms that were used in this study showed promising biofertilizers for raising crop yields.