A pot experiment was conducted at El-Mansoura laboratory of plant nutrition; Agric. Res. Center, during the tow seasons of 2008 and 2009 In order to evaluate the effects of Azotobacter inoculation with and without organic and mineral fertilization on yield and chemical composition of tomato plants.A factorial experiment in the form of complete randomize block design with three replicates has been used. NPK fertilizers were added at the 0,50,75 and 100% of the recommended dose for tomato crop once with inoculation by Azotobacter and the other without inoculation. All treatments were investigated in the presence and absence of organic manure (FYM) giving a total of 16 treatments. Results revealed that inoculation of tomato seedlings with Azotobacter sp. in combination with the rates of NPK fertilizers either with or without FYM significantly gave higher magnitudes of plant growth, yield and its component and chemical composition parameters than the uninoculated treatments. Raising NPK applied levels to 100% of the RD gave insignificant difference during both seasons. In addition, stimulation effect was happened due to using FYM combined with the same rates of NPK fertilization either in the presence or absence of Azotobacter inoculation but the rates of increases over the control treatment were more pronounced during both seasons. The intermediate levels of NPK; 50%+Azotobacter+FYM, seemed adequate and was associated with the highest mean values for the previously mentioned traits.

Pot and field experiments were conducted at the Agric. Exp. Station of El-Mansoura Univ. during the winter season of (2008-2009) and (2009-2010); respectively to investigate the possibility of partial or entirely substituting bio and organic fertilizers for cultivation of wheat plants instead of inorganic fertilizer. Forty treatments were arranged in a split-split block design which were the simple possible combination between, two treatments of farmyard manure; with (FYM) and without were arranged as main plots. Four treatments of NPK fertilizers at the rates of 0, 50, 75 and 100% from the recommended doses by the Ministry of Agriculture and land reclamation (MALR) for wheat plants were randomly located as sup-plots. Wheat seeds were inoculated with biofertilizers and devoted as sub-sub plots as five treatments including; control, cerealin, phosphoren, K-mag and a mixture of them at the rate of 1:1:1. The obtained results indicated that:  The average values of all growth parameters (plant height, fresh and dry weight (g)), yield and its component for the plants treated with FYM were more than that obtained for the untreated plants during both seasons.  For all the aforementioned traits, the average values were increased as the level of NPK-fertilization was increased from 0 to 75% RD. raising the two seasons.  Co-insulated of wheat seeds which the mixture of biofertilizer studied was superior for increasing the average values of all traits, following by the treatments of cerealin, phosphorin, K-mag and finally the untreated one.  The intermediate levels of NPK (75%) + mixture of biofertilizers + FYM seemed adequate and were associated with the highest mean values for the previously mentioned traits. Thus, it could be recommended that inoculation of wheat seeds with the mixture of biofertilizers combined with N, P and K fertilization at the rates of 57, 11 and 14 kg.fed-1 respectively, and farmyard manure ; 20m 3 .fed-1 are considered as the most suitable treatment for realizing the highest economic yield for wheat.