Tow field experiments were carried out at Sakha Agricultural Research Station. Kafr El-Sheikh Government, during two successive seasons of 2010 / 11 and 2011 / 12. The objectives of this research where: (i) increasing wheat yield, (ii) decreasing the applied mineral fertilizer, and (iii) saving irrigation water. Experiments were arranged in split plot design with four replicates .The main plots were assigned to three irrigation intervals, irrigation every (20 (I1), 25 (I2) and 30 days (I3). The sub plots were assigned to three fertilization treatments of F1 (application of the recommended dose of mineral NPK fertilizer, 75, 30 and 48 unit / fed. for N, P and K, respectively). F2 (5 ton / fed. rice straw compost augmented with organic activator +75 % of the recommended mineral fert. (56, 22.5 and 36 unit /fed.NPK). F3 (10 ton /fed. rice straw compost augmented with organic activator + 50% of the recommended mineral fert. 37.5, 15 and 24 for N, P and K, respectively)
The results can be summarized as follows:
1- Irrigation treatment I3 was the best treatment since it save water irrigation of about 10.8% (286 m3) and had no significant decrease in wheat grain yield compared to the traditional irrigation treatment (I2).
2- The highest wheat yield value of 3963.4 kg /fed. Was obtained with I2 F3 treatment, while the lowest one was with I1 F2 .
3- The highest straw yield was obtained by I2 F3 treatment which gave 5.35 ton/fed.
4- The highest protein percentage 11.31 % was obtained by I2 F3.
5- The highest irrigation water productivity (WIP) of 1.40 kg/m3 was obtained with I3 F3 treatment.
6- Water productivity values for I1, I2 and I3 were 1.27, 2.07 and 2.4 kg/m3, respectively indicating a superiority of I3 regime over the others.
7- The highest total organic carbon, organic matter, aggregation parameters and the lowest soil bulk density (1.161 kg/m3), which means the improvements of the soil structure and nutrient uptake, were obtained I2F3 treatment.
8- Therefore, irrigation wheat crop every 30 days with 10 ton rice straw + 50% recommended mineral fertilizer could be recommended for the management of wheat crop under the condition of the studied area.