A field experiment was carried out in sandy soil at El-Ismailia Agricultural Research Station, El-Ismailia Governorate, Agricultural Research Center (ARC) to study the effect of treating the soil with different types of compost (plant residues with organic manure and plant residues with cellulose decomposers), (AM)-mycorrhizae and N₂-fixing bacteria on the growth and yield of wheat plants. Plant dry weight recorded a significant increase when the soil was treated with compost provided with cellulose decomposers and biofertilizers. The highest number of tillers obtained with compost B amended with organic manure and biofertilizers.
The maximum infection percentage was due to compost A provided with organic manure. The optimum nitrogenase enzyme activity obtained when the soil was treated with compost B plus cellulose decomposers and biofertilization. High significant nitrogen percentage was shown when the soil was amended with compost D + organic manure + biofertilizers. inoculation with N₂-fixers + (AM) mycorrhizae led to the increase of phosphorus % and this was clearly obtained with compost "B" plus cellulose decomposers. inoculation with mixed diazotrophs + (AM)-mycorrhizae increased potassium % and this was obtained with compost D plus organic manure at the period of 45 days from sowing.
Results showed significant increases in yield parameters, i.e., 1000-grain weight, grain yield and straw yield. The addition of compost B amended with organic manure + N₂-fixers + (AM) mycorrhizal gave the superior yield. Generally, it was remarkable that the essential role of organic matter represented in compost, N₂-fixers and (AM) mycorrhizae in enhancing the growth and yield of wheat.