This study was carried out in the two autumn seasons 2011 and 2012, in the experiment field of Field Crops Science Department - College of Agriculture - Baghdad, University - Abu - Ghraib. In order to know the response of maize (variety 5012) to organic fertilization under different irrigation periods. A split-plot arrangement R.C.B.D. design was used with three replications. Irrigation periods (4, 8 and 12 days) occupied the main plots, and the fertilization levels occupied the sub plots (F1= organic fertilizer-Pert Humus - 1000 kg.ha-1, F2= 200 kg N.ha-1 +100 kg P2O5.ha-1 and F3= without Fertilizer). The following characteristics were studied: plant height, Leaf area, number of grain. ear-1, 500 grain weight and plant yield.
Results of the experiment showed the following:
The F1 treatment surpassed the other F2 and F0 in all studied traits for the two seasons, the average of plant height (205.5 and 213 cm), Leaf area (6146 and 6121.3 cm2.plant-1), number of grain (593.6 and 597.3 grain.ear-1), 500 grain weight (153.4 and 148.9 gm) and plant yield (182.5 and 181.4 gm) for the two seasons respectively . While the 4 days irrigation surpassed the other in the same traits, with average (205.5 and 207.6 cm), (5769 and 5765 cm2.plant-1), (539.8 and 549.7 grain, ear-1) (147.4 and 150.8 gm) and (162.3 and 169.3 gm.plant-1) for the abovementioned traits for the two seasons respectively. As shown, a significant interaction between studies factors, where F1 treatment with 4 days irrigation outperformed in all studied traits. However, the F1 treatment with 8 days irrigation significantly outperformed of the F2 treatment with 4 days irrigation in plant yield by 181.8 and 189.2 gm for the two seasons respectively