Article Info Received : 05.01.2016 Accepted : 18.04.2016 Lettuce plants were grown under sandy soil conditions in the private farm of Ahmed Orabi organization, Cairo Governorate Egypt, between 15 th November 2009 and 15 January 2010. The experiment was conducted to assess the effects of different nitrogen sources, slow release N (urea-formaldehyde) and fast release N (urea) containing fertilizers at the rates of 0, 60, 90 and 120 kg N ha -1 applied alone or combined with potassium sulphate, on lettuce plant yield. Results indicated that application of different sources of N alone or combined with potassium sulphate gave the highest fresh dry weight per plant and total lettuce yield per hectare compared with the control. The highest dry weight of lettuce was achieved with the combination of urea and potassium sulphate. Although fertilization made with the combination of urea and potassium sulphate resulted in the highest P, K, Zn and Mn contents in lettuce plant, fertilization with urea alone gave the highest N and Fe contents. The lowest content of nitrate in lettuce plants was recorded with the fertilization of urea only or with the combination of urea and potassium sulphate. Application of the combination of urea and potassium sulphate induced the highest protein content in plants. The results indicated that application of urea-formaldehyde as a slow release nitrogen fertilizer solely or combined with potassium sulphate significantly improved yield and yield quality of lettuce plants grown in sandy soil.

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Completely randomized field experiments were conducted at El-Arish Agricultural Research Station, North Sinai, during the winter season of 2005/2006 and the summer one of 2006. The effect of Super Absorbent Polymers (SAPs) combined with local bentonite in the ratio of 1:20 (w/w), was studied on soil chemical and hydrophysical characteristics and some morphological growth parameters as well as the yield production of faba bean (Vicia faba L.) and corn (Zea maiza) grown under drip irrigation system and natural drainage conditions. Soil conditioner was applied in the rate of 0, 1.5, 2.0 and 2.5 ton/fed.Obtained results reveal that soil chemical properties, i.e., EC, pH, soluble cations and anions as well as SAR values are directly affected by increasing conditioner application rate. Modification in soil textural class from sandy to sandy loam was existed with the increase in clay content. Bulk density, macro-pores and saturated hydraulic conductivity values were markedly decreased, while the values of total porosity, water holding capacity, field capacity and available moisture were progressively increased. The greatest improvement in these soil characteristics is pronounced under the highest rate of conditioner doses. Moreover, growth parameters of the two crops as well as their seed yields were beneficially increased with increasing the rate of applied conditioner. This reveals to the highly magnitude of combining synthesized and natural conditioners in a proper amount to improve El-Arish sandy soils properties and enhancing their productivity.

The experimental fieldwork was carried out in sugarcane production areas in Upper-Egypt at Qena Governorates during growing season 2010-2012. Sugar cane is the major source of sugar production in Egypt. Insect pests are limiting factors affecting its production. One of which, is the soft scale insect, Pulvinaria tenuivalvata (Newstead) (Hemiptera: Coccidae). As a new pest, it threatens sugar cane cultivation in Egypt. High scale densities cause significant reduction in sugar cane weight and juice quality, particularly sucrose content. To avoid the sugar cane infection with the soft scale insect, (Pulvinaria tenuivalvata), it is necessary adding diesel fuel through irrigation water. But in the cultivated areas using gated pipes system, irrigation water flowing through closed pipes from branch canals to the fields. It is difficult to add diesel fuel into these canals. Therefore, this paper describes design and locally manufactured of a simple and inexpensive fertilization system suitable of small holding in Egypt called "Vacuum Fertilization System" using in both function, add diesel fuel or any chemicals and fertilization system through gated pipes or any piping closed system during irrigation operation, in spit of, their were another systems using solution fertilizer; but these systems are not available directly in this region and its expensive. Also, evaluating the performance of the designed mechanism in performing this operation. The results showed that: 1-There were a drop in the pressure head measured at the first portion of the gated pipe due to accumulative friction head losses effect and then there were a gradual increase in it due to the increasing in superimposed pressure head, decreased the effect of accumulative friction head losses. 2-The slope of the curve of the actual measured pressure head (hon) along the gated pipe representing the effect of gated pipe length on the pressure head variation, and its value was about 18.2 %. 3-The outlets discharge rate along the gated pipe system were dropped at the first portion of the gated pipe due to accumulative friction head losses effect and then there were a gradual increase in it due to the increased in superimposed pressure head overcome the effect of accumulative friction head losses. 4-The water distribution uniformity along the 18 meter apart of the 6 inch gated pipe before using fertigation system, was about 95.4%. But the water uniformity distribution along the gated pipe during fertigation system using fertilization system was about 93.8%. This mean that the water distribution uniformity decreased slightly during fertigation system using fertilization system under irrigation gated pipe system due to apply the fertilizer through irrigation water, consequently change in irrigation water density affecting outlets flow rates through irrigation gated pipe system. 5-The fertilizer concentration uniformity through the gated pipe system was about 98.1%. This means that, the concentration variation along the gated pipe system was about 1.3%. The reason of t...