Several field trials and laboratory studies were conducted to evaluate the impact of the implementation of the activities and processes of the development of the field irrigation systems at ElMahmoudia area, El-Beheira Governorate, Egypt, during the successful growing seasons winter 2016/17 and summer 2017 to investigate the effect of irrigation systems improvement projects on water productivity. The measurements were conducted in a tertiary canal (Mesqa) at the head of Nekla canal (Arafa Mousa Mesqa). Water consumption values for different crops were calcaulated, and water application was calculated through calibrating the capacities of the pumps and recording the operation hours. The most important results were as follows: Applied irrigation water decreased after irrigation improvement. Applied irrigation water for wheat, rice, maize, sweet potatoes and watermelon before irrigation improvement were higher than the corresponding values after irrigation improvement by 9.0%, 15%, 11%, 15% and 10% respectively. The productivity of wheat, rice, maize, sweet potatoes and watermelon increased after irrigation improvement by 7.0%, 4.0%, 3.0%, 8.0% and 9.0% respectively. Water productivity increased after irrigation improvement, and the increase ratios for wheat, rice, maize, sweet potatoes were 14.0%, 16.0%, 13.0%, 20.0%, and 18.0% respectively.

Two trials were carried out at the Experimental Station farm of Desert Research Center, Teggzerty from Siwa Oasis, Matroh Governorate during the two summer seasons, 2015 and 2016. Trials were performed to study response of two maize hybrids.(Single hybrid 131 and Triple hybrid 329) to organic manure (OM) levels (15 and 30 m3/fed.) and five combinations between mineral and nano nitrogen (N) fertilizers: 1)100% mineral N from the recommended dose (120 kg N/fed.), 2)75% mineral + 25% nano N fertilizers, 3)50% mineral + 50% nano N fertilizers, 4)25% mineral + 75% nano N fertilizers, 5)100% nano N as the recommended rate (500 ppm as foliar application). Mineral N rates were added in three equal doses, with foliar application by nano N rates, after 30, 45 and 60 days from sowing. Treatments, included twenty treatments, was laid out in a splilt-split plot design, with three replicates, OM levels were arranged in the main plots, maize cvs. were allocated in the sub plots, and mineral nano N fertilizer treatments were assigned in the sub-sub plots. At harvest the following characters were recorded, plant height (cm), number of rows/ear, ear length (cm), ear diameter (cm), number of grains/row, 100-grain weight (g), ear weight (ton/fed), grain, straw and biological yields (ton/ fed), shelling (%) and harvest index(%). Results indicated that increasing OM levels significantly increased ear length harvest index and protein content (%), in the 2nd season only, triple hybrid gave the maximum values of all pa rameters, except no. of rows/ear and harvest index, in the 1st season, and 100-grain weight and carbohydrate (%), in both seasons, which had no significant difference with single hybrid in the most cases. Concerning with the effect of mineral and nano N, all parameters, except carbohydrate (%), were increased with increasing mineral N (%) and/or with decreasing nano N (%). Fertilized maize crop by mineral N at 100% or 75% plus 25% nano N fertilizer gave the maximum values of plant ht., no. of rows/ear, ear length and diameter, no. of grains/row, 100-grain wt.,ear weight, grain, straw and biological yields, shelling (%), protein (%), protein yield and harvest index in both seasons. However, fertilized maize crop by nano N at 100% produced the highest value of carbohydrate content (%) in two seasons. Results suggested that selected triple maize hybrid cv. (329), at 30 m3 OM, with 100% mineral N (120 kg N/fed.) or with 75% mineral N (90 kg N/fed.) plus 25% nano N (125 ppm as foliar application) fertilizers could be utilized for attaining the maximal improvement in farmer income by increasing the maize yield under saline conditions at Siwa Oasis, Egypt.

This work aimed to study the effect of FYM rates (0, 10 & 20 m3 fed-1) and application in time of N fertilizer on maize grain yield and its attributes using single cross hybrid 130 at two field experiments. The technique of treatment - trait (TT) biplot graph was used to study the interrelationships among maize traits. The Results showed that application of 10 or 20 m3 FYM and adding the recommended N fertilizer on these doses with first, second or third irrigations gave highest values for the grain yield and most agronomic traits. It is obvious that the highest correlation coefficients were obtained between grain yield and each of number of ears plot-1 (NE),ear length (EL), ear diameter (ED) and 100 kernel weight (KW),under Gemmeiza location, while the traits of days to 50%tassiling and silking, plant height (PH), ear height (EH),   number of ears plot-1 (NE) and 100 kernel weight (KW) were the most associated traits with grain yield under Sids location. Using the TT biplot graph, results revealed that the best performance treatments for most studied across the two locations were the application (T11) before as well as application (T10). The results showed that TT biplot graph was an effective statistical tool to study the effects of treatments on yield and its attributes and also to discover the interrelationships among these traits. Accordingly, the maize breeder should give interest in the interrelationships among grain yield and its attributes when planning the breeding program.