RATIONALIZATION OF IRRIGATION WATER AND NITROGEN FERTILIZERS FOR WHEAT BY USING MICROBIAL INOCULANTS UNDER TWO SURFACE IRRIGATION METHODS

Two field experiments were carried out at Sakha Agricultural Research Station, Kafr El-Sheikh Governorate, North Middle Nile Delta region during the two successive winter growing seasons of 2008/2009 and 2009/2010. The main objective of the study was to decrease the amount of nitrogenous fertilizers by using the fixed nitrogen bacteria and microbial inoculants and their effects on wheat productivity under two surface irrigation methods. Also, this work aims at comparing the two surface irrigation methods for wheat irrigation, identification the best irrigation method for both wheat and rationalization water consumption and studying some water relations. The experimental design was split plot with four replicates. The main treatments were irrigation methods, A₁ basin irrigation and A₂ corrugation while the submain treatments were fertilization and application of microbial inoculants; B₁ mineral nitrogen, B₂ raise the available nitrogen in the soil till the recommended dose, B₃ 50 unit of nitrogen + Azospirillum inoculation and B₄ 50 unit of nitrogen + Azospirilluminoculation + Humates incorporated by micronutrients.
The obtained results can be summarized as follows:
1.  The values of applied irrigation water were increased under basin irrigation method (A₁) comparing with corrugation one (A₂). Data also showed that the values of applied irrigation water were not affected by fertilization treatments.
2.  The highest values of water consumptive use were recorded under basin irrigation method (A₁) in the two growing seasons comparing with the corrugation one (A₂). Concerning with fertilization effect data indicated that the highest value was recorded under B₄ treatment. Also, data illustrated that the highest mean values were recorded under A₁B₄ and A₂B₄ in the two seasons.
3.  The highest mean values of both water utilization efficiency (W.ut.E) and water use efficiency (W.U.E.) were recorded under corrugation irrigation method (A₂) comparing with basin irrigation one (A₁) and the highest values were recorded under A₁B₄and A₂B₄ in the two seasons.
4.  The mean values for wheat grain yield were increased under basin irrigation (A₁) comparing with corrugation one (A₂). For the effect of fertilization on wheat grain yield the best treatment was B₄.
5.  The mean values for straw yield, biological yield, harvest index and 1000-grain weight were increased under local surface irrigation method (A₁) comparing with corrugation one (A₂) in the two seasons. Data also showed that the above mentioned studied parameters were increased under B₄ fertilization treatment in the two seasons and the mean values can be descended in order B₄ > B₃ > B₂ > B₁.