THE EFFECT OF Azotobacter chroococcum (A22 ISOLATE) ON IMPROVING THE GROWTH AND NUTRIENTS ABSORPTION OF MAIZE PLANTS TREATED WITH DIFFERENT LEVELS OF NITROGEN AND GROWN UNDER DIFFERENT SALT LEVELS
NAJWA R. SAEED *
College of Agriculture, University of Basrah, Iraq.
ABDUL-ZAHRA T. THAHER
College of Agriculture, University of Basrah, Iraq.
*Author to whom correspondence should be addressed.
Abstract
The pots experiment was carried out in the canopy wired, College of Agriculture, University of Basrah, during 2018 season, to determine the effect of Azotobacter chroococcum (A22 isolate) to improving the growth of maize grown in salt-affected soils, the experiment included four levels of nitrogen 0, 50, 75 and 100% of the nitrogenous fertilizer recommendation of 150 kg N.ha-1, with three levels of Salinity 3, 6 and 12 ds.m-1 and two inoculates with (A22 isolate), un-inoculate to estimate the growth and the absorbed amount of N, P and K. The results showed that A22 isolation inoculate increased a dry weight by 22.25% and the absorbed amount of N, P and K by 37.04, 89.4 and 27.6% respectively, compared with control un inoculates, inoculation with this isolate A22 reduced the nitrogen fertilizer recommendation by 25% and improved the growth of maize under salt stress conditions.
Keywords: Azotobacter chroococcum bacteria, A22 isolate, maize, nitrogen, salt