Two field experiments were conducted at Sakha Agricultural Research Station Farm, Kafr El-Sheikh Governorate, Egypt (31 o 05 ' N latitude and 30 o 56' E longitude) during 2009/2010&2010/2011 winter seasons to investigate the response of some wheat varieties to different N levels. Split plot design with four replicates was applied, the main plots were assigned to four wheat varieties, Gimiza 9, Giza 168, Sakha 61 and Sakha 93. The subplots were assigned to four nitrogen levels of 0, 30, 60 and 90 kg N/fed. (fed. = 0.42 ha.). The obtained results can be summarized as follows: 1-Wheat varieties significantly differed in grain, straw and biological yields, as well as harvest index, N%, N uptake and protein content in the two seasons. 2-Gimiza 9 variety had the highest mean value of grain, straw and biological yields, and N uptake and protein content of grain and straw. 3-The grain, straw, biological yields, N uptake and protein content were significantly increased by increasing N levels. 4-The interaction between wheat varieties and N levels showed that Gimiza 9 variety had the highest value of grain yield (2822.0 kg/fed) followed by, Giza 168 (2681.0 kg/fed.), Sakha 93 (2552.0 kg/fed.),and Sakha 61 (2475.0 kg/fed.), with N90 level. 5-The highest N uptake and protein content of grain and straw were obtained by Gimiza 9 with N90 level and the lowest value by Sakha 93 under N0 level. 6-Gimiza 9 had the highest net return value of 8663.75 L.E./fed. followed by Giza 168

A field experiment was conduced during the summer seasons of 2005 and 2006 at Disuq district, Kafr El-Sheikh Governorate to study the combined effect of inoculation with Halex-2 (as biofertilizer) and mineral nitrogen levels on cowpea yield and their net return.Split plot design was used with four replicates. The main plots were assigned by two treatments of uninoculated (control), and inoculated with Halex-2. Whereas, the sub-plots were assigned by five N levels (0, 10, 20, 30 and 40 kg N fed -1 ). Four polynomial quadratic equations were established to show the following results:1. The maximum and optimum N rates were decreased as Halex-2 used in the two seasons. 2. The maximum and optimum cowpea yields were increased as Halex-2 used in the two seasons. 3. The highest maximum yield (1413.2 kg fed -1 ), the highest total value of yield (7065.0 L.E fed -1 ) and the highest return of bio and N fertilizer (2936.6 LE fed -1 ) were obtained as Halex-2 used in the first season. 4. The average of efficiency and the efficiency of nitrogen fertilizer at optimum rate were increased as Halex-2 used. 5. The soil nitrogen content during plant growth (Xs) was increased as Halex-2 added. 6. The contribution of soil N was increased as Halex-2 used in the two seasons. 7. The contribution of N fertilizer was increased as N levels increased in the two seasons.

Two field trials were carried out at Sakha Agric. Res. St. farm during two successive winter seasons of 2007/2008 and 2008/2009, to assess the effect of planting methods and phosphorus fertilization treatments on faba bean yield, nutrient contents and some water relationships. Faba bean (Vicia faba L.) seeds var. Sakha 2 were planted on November in both seasons. Split plot design was used with four replicates. The main plots were assigned by two planting methods i.e. A: 120 cm furrow spacing with 4 planting rows per furrow and B:60 cm furrow spacing with 2 planting rows per furrow. The sub plots were assigned by four phosphorus treatments .e.1-application of 30 kg P2O5 fed-1 (ha = 2.4 fed.) as superphosphate 15.5% P2O5 (P2O5 = 2.29 x P) , 2-completing the soil available phosphorus up to 30 kg P2O5 fed

winter season, to assess response of some wheat (Triticum aestivum L.) varieties to the nitrogen fertilization levels by determining the dry plant weight, daily increase, N% in the dry matter, nitrogen uptake during the growing periods and nitrogen uptake during the physiological stages. Split plot design with four replicates was used, the main plots were assigned by four wheat varieties of Gimiza 9, Sakha 61, Sakha 93 and Giza 168. The subplots were assigned by four nitrogen levels of 0, 30, 60 and 90 kg N fed. 1 (ha = 2.4 fed.). Eight plant samples were collected during the growth periods to determine the previous traits. The obtained results can be summarized as follow:  Gimiza 9 and Giza 168 had the higher dry plant weight of 6.64 and 6.95 (g/plant) compared to Sakha 61 and Sakha 93 of 5.97 and 5.98 (g/plant).  Dry plant weight was increased with increasing nitrogen levels.  The highest daily increase of Gimiza 9 was (138 mg/day) at 97-111 days period, Sakha 61 was (97 mg/day) at 69-83 days period, Sakha 93 was (102 mg/day) at 83-97 days period and Giza 168 was (140 mg/day) at 61-69 days periods.  Nitrogen % was higher in the first growth period and decreased with time and was increased with increasing the nitrogen levels.  Giza 168 had the highest nitrogen uptake (145.27 mg N/plant) there was no significant difference between Gimiza 9, Sakha 61 and Sakha 93.  Nitrogen uptake was increased from 71.16 to 129.04, 158.18 and 173.3 (mg N/plant) with increasing the nitrogen levels from 0 to 30, 60 and 90 kg N fed.-1 respectively.  Gimiza 9 absorbed 23.57% of total nitrogen uptake at tillering, 46.12% at head development stage and 30.32% at flowering stage.  Sakha 61 absorbed 26.06%, 49.19% and 24.76% from total nitrogen uptake at tillering, head development and flowering stages, respectively.  Sakha 93 absorbed 23.55%, 42.22% and 34.23% from total nitrogen uptake at tillering, head development and flowering stages, respectively.  Giza 168 absorbed 22.54%, 46.34% and 31.12% from total nitrogen uptake at tillering, head development and flowering stages, respectively.

Two field experiments were carried out at Wady Elnatron, El-Behera Governorate, "Wady Elnatron located in the west desert near the Delta about 90 kilometers north west of Cairo", during 2008 and 2009 seasons to study the effect of irrigation water amounts and nitrogen rates on maize yield and the net return from these treatments under drip irrigation system. Split plot design was used with four replicates. The main plots were assigned by four irrigation water amounts (100 %, 90 %, 80 % and 70 %) of evapotranspiration (ETc). The sub-plots were randomly assigned by four nitrogen rates (zero, 50, 100 and 150 kg N fed.-1 ) as ammonium nitrate (ha = 2.4 fed.). The other recommended agriculture practices were done. Four polynomial quadratic equations were established to show the following results: 1. The maximum and optimum N rates (Xm and Xopt) were increased by decreasing irrigation water amounts from 100% to 70% of ETc in the two seasons. 2. The maximum and optimum maize yields (Ym and Yopt) were decreased by decreasing irrigation water amounts from 100% to 70% of ETc in the two seasons. 3. The highest maximum yield (4.307 ton fed.-1 ), the highest total value of yield (6394.5 L.E fed.-1 ) and the highest return of N fertilizer (1744.5 LE fed.-1 ) were obtained with 100 % of ETc used in the two seasons. 4. The efficiencies of N rates (eX) were decreased by increasing N rates from N0 to N1, N2 and N3, respectively with different irrigation water amounts. 5. The relative efficiency (EX), the efficiency of nitrogen fertilizer at optimum rate (eXopt) and the efficiency of soil nitrogen (eXs) were decreased as irrigation water amounts decreased. 6. The soil nitrogen content during plant growth (Xs) was decreased as irrigation water amounts decreased. 7. The contribution of soil N was decreased as irrigation water amounts decreased in the two seasons. 8. The contribution of N fertilizer was increased by increasing N levels in the two seasons.