الفهرس Only 14 pages are availabe for public view
 |  | from | 101 |  |  |
| | | from | 101 | | |
Abstract
Two field experiments were carried out during 1997/98 for cultivating two important grainous crops, namely wheat (as a winter crop) and maize (as a summer crop). The effect of different techniques of nitrogenous bioferilization (grain and philosopher inoculation) by using Azotobacter chroococcum, Azospirillum sp and N2 fixing bacilli singly or in a mixture of all of them) on plant growth and their chemical composition (total N, total amino acids and total carbohydrate was periodically evaluated. Microbial densities and nitrogenase activity in both rhizosphere and phyllosphere were also estimated during different periods of plant growth. At the end of experiments, straw and grain yield’ of both crops and. their chemical constituents were also determined. These were carried out in the presence of different doses of chemical N¬ - fertilizer (urea). The obtained results clearly show that application of a mixture of asymbiotic N2 fixers namely Azotobacter chrooco¬ccum, Azospirillum sp. and N2-fixing bacilli can save about 50 or 25% of the recommended field dose of chemical N-fertilizer by grain or philosopher biofertilization respectively.