Aim: In order to study the effect of biochar, bentonite and potassium humate on saline soil characteristics, barley growth and nitrogen loss, a column experiment was conducted. Addition of the above mention materials was hypothesized to improve the characteristics of saline soil and decrease nitrogen loss in the leachate solution. Place and Duration of Study: Farm of Soils and Water Department, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt during the winter season of 2019. Methodology: Biochar and bentonite were added with rates 0, 5 and 10 g.kg-1; and the rates of potassium humate were 0, 5 and 10 mg.kg-1. Excess irrigations were implemented three times (on 12th, 24th, 36th days) during growing season. Leachate solution was collected after each excess irrigation from each column to determine nitrogen loss. Results: Main results show that total organic carbon and soil porosity were increased by increasing the addition rates of the studied materials, especially at the high rates of biochar and bentonite. Also, the availability of water significantly increased. Addition of biochar and bentonite gave the highest decreasing in leachate solution volume. Nitrogen loss was decreased significantly at the highest rates of the studied materials, where the decrement percentage in leachate solution reached at 36.07%, 35.82 and 23.81 at the highest rates of biochar, bentonite and potassium humate, respectively. That led to increasing the retention of available nitrogen in saline soil. Fresh and dry weights of barley plants were increased significantly by increasing the addition rates of all amended materials. Macronutrients (NPK) content and uptake were increased significantly by increasing the addition rates of the studied materials. Conclusion: Research results proved that changes in soil properties caused a significant increase in barley growth and nutrients uptake. Addition of biochar and bentonite were the best option for improving saline soil properties, barley growth and nutrients uptake and reduce nitrogen loss by improving nitrogen retention and decreasing the leachate volume.

The present study was carried out to treat wastewater and investigate its impact on wheat growth, uptake of nutrients and heavy metals. To achieve this task, two experiments were conducted at the Faculty of Agriculture, Al-Azhar University-Cairo-Egypt, during winter season of 2014. The 1 st (lab experiment) was for treatment wastewater by using moringa seeds and chitosan with different doses (0.5, 1 and 2g/l as powder and 1, 2 and 3 % as extract). The 2 nd (pot experiment) was carried out to investigate the effect of the previously treated wastewater on wheat growth, uptake of nutrients and heavy metals.The main results from the first experiment showed that heavy metals concentration in wastewater decreased significantly by increasing the addition of the added materials. Moringa seeds and chitosan as powders were more effective than its extracts. Results from the second experiment indicated that there was an increase in both fresh and dry weight of wheat plant irrigated with treated wastewater compared with control. Also, the highest values were observed at the highest dose of chitosan extract (3%). On the other hand, the uptake of N, P and K by wheat plants increased significantly by increasing the added materials. Moreover, the heavy metals uptake by wheat plant (µg/plant) was decreased by addition of the treated materials. Sayed A. AbdeenChitosan biopolymer has a possess electro-static properties to adsorb metals according to ion exchange mechanism. The adsorption properties of chitosan biopolymer are attributed to its functional group including increase of hydrophilicity by hydroxyl groups of the polymer. This helps to enhance the diffusion of polymer networks and allows adsorbing metals from aqueous solutions. Amino groups of chitosan are very important for adsorption processes compared to hydroxyl group, for which degree of deacetylation is an important parameter to evaluate the quality of the chitosan biopolymer (Crini 2005) .The mechanism of metal ions removal by chitosan is shown in Figure (1).

Many problems facing sandy, calcareous and heavy clay soils and restricts plant growth, nutrients availability and sustainable agriculture. Soil amendments are considered to be the most realistic soil management methods to improve soil chemical and physical properties. Improving some soil physical and chemical properties, study the correlation between soil properties and their effect on plant growth and nutrients uptake by faba bean plant (Vicia faba L. var.716) were the main purpose of this study. To achieve this purpose three factorial pot experiments were conducted by addition rates (0, 5 and10 ton. fed -1 ) of farmyard manure (FYM), phosphate rock (PhR) and rice straw (RS) either alone or mixed to sandy, calcareous sandy loam and clay soils. Soils were incubated with the studied treatments for 15 days before planting. The main results showed that the addition rates of soil amendments led to slightly increase in soil salinity, total porosity and significant increase in organic matter content in the experimental soils. Bulk density and pH decreased with increased the rates of FYM and PhR either alone or mixed with RS. Decreasing in hydraulic conductivity in sandy and sandy loam soils, while it increases in clay soil. Generally, there are negative correlations between soil organic matter and both of hydraulic conductivity and bulk density in sandy and sandy loam soils, while, organic matter and hydraulic conductivity gave a positive effect in clay soil. Changes in soil properties had a positive effect of faba bean growth and macro nutrients uptake. The highest rates of the studied materials showed a significant increase in fresh and dry weight, NPK content and uptake of faba bean plant. Integrated use of the highest rates of FYM and PhR with RS were the best option for sustaining physical and chemical properties, enhancing faba bean growth and nutrients uptake of the studied soils.

The present experiment was carried out in a plastic house of Soils and Water Department, Faculty of Agriculture, Al-Azhar University )Nasr City, Cairo, Egypt) to study the effect of two isolates of blue green algae to Hoagland nutrient solution on yield, chlorophyll content of lettuce (Lactuca sativa L. cv. Big Bell) using Nutrient Film Technique (NFT).The content of nitrate as well as some macro and micronutrients were taken into consideration. This study aimed to reduce the use of inorganic nitrogen fertilizers for their side effect on human health and high cost, by adding algae as a bionitrogen source to the nutrient solutions. The addition of algal isolates (either N. pruniformeor or A. fertilissima) to Hoagland nutrient solutions caused a significant increase in the fresh and dry weight of the leaves of lettuce, chlorophyll and nitrogen contents as compared with Hoagland nutrient solution minus N. The most favourable of these results were attained by the addition of algal isolates to 0.75 strength of Hoagland nutrient solution as compared with full strength of Hoagland nutrient solution. Also, the addition of algal isolates to 0.5 strength of Hoagland nutrient solution caused a significant increase in the above parameters as compared with half strength of Hoagland nutrient solution. On the other hand, the poorest results were noted in the treatment of Hoagland nutrient solution minus N whereas; the addition of algal isolates (either N. pruniformeor or A. fertilissima) to this treatment caused a significant increase in all tested parameters. In conclusion, this study confirmed that the addition of algae to the nutrient solutions under NFT can reduce the use of inorganic nitrogen fertilizers. On the other hand, the relative reduction in the yield of lettuce due to the addition of algae to nutrient solutions minus nitrogen can be acceptable if we take into consideration the safe use of plants due to low content of nitrate and reducing the use of inorganic nitrogen fertilizers.

Soil compaction considered a problem that affects several soil properties and plant growth parameters. In order to assess the effects of soil compaction (expressed as bulk density) under different levels of moisture content and rice straw on some soil properties, plant growth parameters and macro nutrients uptake by sorghum plant (Sorghum bicolor (L.) Moench, Dorado sp.