Two field experiments were carried out in Ismailia Agricultural Research
Station. Agricuttural Research Center during 200212003 and 200312004 to study the
effect of seeding rates (60 and 80 kg seeds/fed.) and inoculation with free living
(Azotobacter) and associative (Azosp < /em>irillum) N:z-fixers in a form of single or dual
inoculum together with two rates on N.lertilizer (60 and 90 kg Nlfed), in addition of
treatment received 120 kg Ntted only on growth, yield and yield components of wheat
plants (Giza 168) grown in sandy soils. A split plot design with three replications was
used. The results of the combined analysis of the two growing seasons 200212003
and 2003/2004 indiceted that :-
1· Seeding rate of 60 kg seed/fed. significantly increased numbers of tillers/plant,
spike length, number of grains/spike, 1000-9rain weight, grain yield and total
protein (kg/fed.) while, ao kg seed/ted. significantly increased plant height. number
of spikesfm2, straw yield and protein percent.
2· Results also revealed that no Significant differences could be observed due to
inoculation with both Azotobacter or Azosp < /em>irillum on all the tested parameters.
However, Azotobader gave values higher than Azosp < /em>iriJlum, bu1 the values didn't
reach to the level of significancy. Taking blofertilization "";th mixed culture of
Azotobacler and Azospirillum together v.ith 90 kg Ntted into account, results
showed an increase in grain yield by about 2.7% over mineral N application (120
kg N/fed). Such results indicated that biofertiiization could save at least 25% of
recommended nitrogen, besides its role in reducing pollution associated with
mineral nitrogen application.
:I. The interaction between seeding rate and biolertilization clearly indicated that seed
rate of 60 kg Nffed when inoculated v.ith mixture of free and associative N:z-fixers
was superior in achieving yield and yield components, grain yield and protein yield
and was more efficient in increaslnq total N recovery.