An attempt made to isolate Azotobacter chroococcum from ten-soil rhizosphere of different crops in Dhi Qarprovince. Five samples collected from soil, which previously treated with pesticides and other five samples collected from soil not treated with pesticides in order to use these Azotobacter isolates as biofertilizer and study it is effect on the growth of barley. The results showed that the plant hight and shoot & Root dry weight were increused due to inoculation with Azotobacter and the highest value recorded with isolates B3 and B4 in compare with B9 and B10 isolates, which gave the lowest value. The increasf of Ristart concentration from zero to 1500,3000 and 6000 cm3.ha-1 were caused significently elecreasing in shoot dry weight to (61.65,54.88 and 36.84)% respectively while the root dry weight were decreased to (52.00,41.33 and 26.66)% for three above concentrations. The Ristart pesticide caued significantly decrease the Azotobacter numbers after 60 days of planting and the height olensity recorded with the isolates B3 and B4 isolates compare with B19 &B10 isolates, which gave the lowest numbers.
Mohammed Saeed Haran, AL−Shatrah Technical
Ali Salem Hussein, South Technical University Institute