TWO FIELD experiments were carried out at Zarzoura, Itay El-Baroud, Agricultural Research Station, El-Behaira Governorate, Agricultural Research Center (ARC), Egypt during 2014 and 2015 seasons to study the effects of three nitrogen fertilizer levels on yield and yield components under two intercropping soybean/maize patterns. The results indicated that, the highest ear length, ear diameter, No. of rows per ear, grain yield per ear (for maize), seed yield per fad (for soybean) and the better (the lowest) competitive ratio values were found with treatment intercropping patterns 2 maize: 4 soybean (CP2). While the highest grain yield per fad (for maize), No. of pods per plant, seed yield per plant (for soybean), total LER (land equivalent ratio), the percentage land saved, total AYL (actual yield loss) and WUE (water use efficiency) values were occurred under intercropping patterns 2 maize: 2 soybean (CP1).
Moreover, plant height, ear length, No. of grains per row, grain yield per fad, ear height, ear diameter, No. of rows per ear, grain yield per ear,100- grains weight (for maize), plant height, No. of branches per plant, No. of pods per plant, seed yield per plant and per fad (for soybean), total LER, the percentage land saved, total AYL, aggressivity and WUE values were increased with the increment in nitrogen level, and the highest values were obtained with 120 kg/fad, while the lowest values were obtained with 80 kg/fad. On the other hand, No. of seeds per pod and 100 seed weight for soybean had a negative relationship with the level of nitrogen applied and its highest values were obtained with 80 kg/fad.