Productivity of maize under water stress conditions and biological fertilization in calcareous soils

الملخص EN

Two field experiments were conducted in 2003 and 2004 summer seasons at Desert Research Center Experimental Station at Maruyt to investigate the response of maize cv.

30B9 to different bio-fertilization treatments (Azotobacter crococcum Mycorrhiza + Pseudomonas spp) and (Azospirillum lipoferum + Bacillus megatherium var.

phosphaticum + Bacillus sabtilis) accompanied with two mineral NPK levels (full and half dosages), under four water regime treatments; which missed one irrigation (the second, the third, or the fourth) beside the normal irrigation treatment as a control. Results proved that water is a limiting production factor of maize plants; meanwhile maize plants can tolerate water scarcity at the vegetative growth period (60 days).

Missing the fourth followed by the third irrigation seemed to be the worst treatments compared with the other treatments, while missing the second irrigation treatment seemed to be the best after the control one.

The application of the bio-fertilization treatments help the plants to overcome the bad effects of water stress at any growth period.

The first bio-fertilizer (Azotobacter crococcum + Mycorrhiza + Pseudomonas spp) seemed to be more successive under water stress conditions compared with the other treatment Azospirillum lipoferum + B.

megatherium var.

phosphaticum + B.

sabtilis).

Under the normal irrigation conditions, the full dosage of the mineral NPK fertilizers seems to be the best followed by both first and the second bio fertilizers accompanied with the half dosage of the mineral NPK .When taking into consideration the environmental expenses, using the half dosage of the mineral NPK + the bio fertilizers will be more logic.

Results indicated that under normal irrigation, the full dosage of mineral NPK fertilizers followed by the combination of both the first then the second bio-fertilizer and half dosage of mineral NPK increased significantly the plant growth parameters (plant height, plant fresh, dry weights, and leaf area) in addition it increased significantly pigments accumulation, total chlorophyll content, N, P and K.

These results increased significantly ear weight, number of grains per ear, 100 grain weight, consequently biological and grain yield.