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Two field experiments were carried out at El-Gemmeiza Agricultural Research Station, El-Gharbia Governorate during the two summer growing seasons, 2007 and 2008 to study the effect of nitrogen fertilizer rates, i.e., 15, 30 and 45 kg N/fed and foliar application of compost extract & humic acid on yield components, yield and chemical composition of rice plants and nitrate as well as nitrite content in drainage water at different stages from transplanting. Results can be summarized as follows:-Generally, high level of nitrogen fertilizer achieved significantly increases of rice yield and its components as well as N, p & K content of grain and straw compared with low rates in both growing seasons. While, in most cases, the same trend was recorded when second level of 30kg N/fed was practiced.Spraying humic acid or compost extract led to significant increases in most parameters of yield and its components as well as N, p & K content of grains and straw compared to no addition of such organic compounds in both seasons.In most cases, the interaction effect between the factors under study was insignificant on rice yield and its components as well as macronutrients content of grains and straw in both seasons.The high level of nitrogen fertilizer achieved significantly increases of nitrate and nitrite content in drainage water at different stages from transplanting compared to low rates in both stages of two growing seasons. On the other hand, such parameters weren't significant affected by foliar application of humic acid, compost extracts or the interaction between them and nitrogen levels in both seasons.

Field experiments were conducted at El-Gemmaza Station Farm, during 2012 and 2013 seasons to study the response of rice crop to phosphorous and sulfur fertilizations. Sakha 105 rice cultivar was used. The experiments were laid out in split plot design with four replications; the net plot size was 10 m 2. The main plots were designated for phosphorus treatments and the sub-plots for sulfur treatments. The phosphorus treatments were 0, 18, 37, 55 kg P2O5 ha-1 denote P0, P18, P37 and P55, while, the sulfur treatments were 0, 47, 95 and 142 kg S ha-1 denote, S0, S47, S95 and S142. The main results could be summarized as follows, phosphorous application as signal significantly and positively affected rice grain yield in both seasons of study. At the same time significant improving in grain yield were detected as a results of significant improvement in yield attributes by phosphorous application. The optimum rate of P was 37 kgP2O5 ha-1 at the first season and 55 kg P2O5 ha-1 in the second season. Sulfur application significantly improved growth, yield and yield attributing traits in both seasons of study. Yield and yield attributes significantly responded to sulfur fertilizer up to 95 kg S ha-1 in both season and increasing sulfur rate beyond this rate slightly decreased the yield and yield components. Regarding the interaction effect, the interaction between sulfur and phosphorous had significant effect on dry matter (gm-2), number of tillers hill-1 , Number of panicles hill-1 , number of filled grains panicle-1 and grain yield tha-1 in both seasons. the optimum combination of phosphorus and sulfur was P37S95. The interaction effect on rice grain yield, in the first season, grain yield recorded its maximum value at the combination of P37S95 in the first season. It is noted that P35S95 combination occupied the second order after P55S95 without significant differences in the second season. The combination of P37S95 could be recommended under such conditions for optimum rice grain yield .

seasons, selection was performed in M2, M3, M4, M5 and M6 generation. Sixteen homogeneous and stabile lines were grown during 2013 season under different conditions in three locations (Sakha, Gemmiza as normal soil and EL-Sirw as saline soil stations). The experimental design was a split plot design with four replications. The main plots were devoted to irrigation intervals, while, sub plots were devoted to induced mutants under different conditions in three stations. During 2014 and 2015 seasons, all the induced mutants were evaluated in RCB design with four replications under conditions of Sakha Agric. Res. Station. Data were recorded on days to maturity (day), 1000-grain weight, grain yield (t/ha) and yield reduction %. Data were recorded on days to maturity (day), 1000-grain weight, grain yield (t/ha) and yield reduction %. The desirable values of early maturity, grain yield (t/ha) and grain yield reduction were recorded for Giza 178 M8-4, Sakha 104 M8-4,101 M8-4, and Giza 177 M8-4under different irrigation intervals 3, 6 and 9 days in different research stations (Sakha, Gemmiza and El-Sirw) during 2013 season. Also, these mutants of Sixteen Entries were differed in Sakha Research Station during 2014 and 2015 seasons, whereas, Giza 178M8-4, Sakha 104 M8-4, Sakha 101 M8-4 and Giza 177 M8-4 recorded the desirable values for days to maturity and highest values for 1000 grain weight and grain yield, Sakha 101 M8-4, Giza 177 M8-4, Giza 178M8-4 and Sakha 104 M8-4 could be used as new promising lines tolerant to stress conditions better than their parents.