Efficient utilization of available water resources in arid area of Egypt (The New Valley area) is crucial. Toward having a good and high efficient water management the determination of crop water requirement is appreciable. Many methods has been adopted to be used and required to be validated. The objectives of this study were to calibrate and validate some ETo models using lysimeter under the New Valley conditions. Estimation of accurate ETo under these climatic conditions was also considered. Nine non-weighing lysimeters were installed, planted with alfalfa as a reference crop. Daily and monthly values of twelve ETo models were compared with Lys-ETo during February 1st 2013 to January 31st 2015. The comparison was first made using original constant values in each ETo model, then the selected models were calibrated as second step using data of first year through modified constant values involved in each model. In the last step, calibrated models were validated using both measured and estimated ETo data of second year. The comparative study indicated that the original FAO-24 Radiation and Blaney- Criddle models gave the lowest values of RMSE and RRMSE as compared with Lys-ETo, they were 0.90 mm day-1 and 10.24% for FAO-24 Radiation and 1.37mm day-1 and 15.58% for Blaney-Criddle, respectively. Also, locally calibrated FAO-24 pan model was the best model and gave the excellent coinciding as compare with the Lys-ETo observations under the New Valley conditions.

Efficient utilization of available water resources in arid area of Egypt (The New Valley area) is crucial. Toward having a good and high efficient water management the determination of crop water requirement is appreciable. Many methods has been adopted to be used and required to be validated. The objectives of this study were to calibrate and validate some ETo models using lysimeter under the New Valley conditions. Estimation of accurate ETo under these climatic conditions was also considered. Nine non-weighing lysimeters were installed, planted with alfalfa as a reference crop. Daily and monthly values of twelve ETo models were compared with Lys-ETo during February 1st 2013 to January 31st 2015. The comparison was first made using original constant values in each ETo model, then the selected models were calibrated as second step using data of first year through modified constant values involved in each model. In the last step, calibrated models were validated using both measured and estimated ETo data of second year. The comparative study indicated that the original FAO-24 Radiation and Blaney- Criddle models gave the lowest values of RMSE and RRMSE as compared with Lys-ETo, they were 0.90 mm day-1 and 10.24% for FAO-24 Radiation and 1.37mm day-1 and 15.58% for Blaney-Criddle, respectively. Also, locally calibrated FAO-24 pan model was the best model and gave the excellent coinciding as compare with the Lys-ETo observations under the New Valley conditions.

The aim of this study was to investigate the effect of some pesticides (Methomyl, Deltamethrin and Chlorpyrifos), zeolite, silica gel and ferric oxide on the immobilization of some heavy metals (Cd, Ni, Cr and Pb) in sewage sludge. The results indicated that the application of 3 g of Deltamethrin 100g-1 sludge decreased the DTPA- extractable content of Cd, Ni, Cr and Pb by 25, 21, 46 and 16%, respectively. Adding 1.5 ml Chlorpyrifos/100 g sludge caused significant increase in extractable Cd, Ni and Pb by 39, 38 and 16%, respectively, compared with the control treatment. Application of 15% (w w-1) zeolite to the sludge resulted in the maximum decrease in both extractable Cd (from 0.90 ppm in the control to 0.33 ppm) and Pb (from 26.7 ppm in the control treatment to13.4 ppm). Application of 25% silica gel decreased DTPA extractable Cr by 74%. Application of a mixture of silica gel with zeolite or with ferric oxide completely retained all the extractable Ni.

The enhancement of sewage sludge to decrease its toxic effects on living organisms due to the high content of heavy metals (Cd, Cr, Ni and Pb) was studied using some organic and inorganic materials. Four materials (Silica gel, Cement Bypass, Rock phosphate and Charcoal activated carbon) were mixed with the sewage sludge in three rates (5, 15 and 25%) and the mixture of each two materials at a rate of 15% of each. Results indicated that DTPA extractable Cd, Ni and Pb decreased from 0.895, 12.097 and 26.02 ppm in the control to 0.376, 3.13 and 9.06 ppm, respectively (58, 74 and 65% reduction , respectively, compared with the control) with 25% of rock phosphate (RP). The lowest extracted Cr was obtained by the application of 25% silica gel with a reduction of 67% compared with the control. The maximum reduction in extracted Cd, Cr and Pb were resulted by the mixture of charcoal+ silica gel (0.33 ppm Cd), rock phosphate+ Silica gel and cement By-pass+Silica gel (0.04 ppm Cr) and rock phosphate+cement By-pass (9.98 ppm Pb), respectively. While, the mixture of silica gel with any other amendment under discussion always resulted in 100% reduction of extracted Ni.

Two greenhouse pot experiments (clayey and sandy soil) were conducted in order to evaluate the effects of solarization (covering the soil with transparent plastic sheets), inoculation with sulfur oxidizing bacteria SOB (isolated thiobacillus), addition of filter mud cake (one of the sugar industry wastes, Nagaa Hammady Sugar Factory) as a source of organic matter and elemental sulfur (granule or micronize) on some sand and clay soil properties. In both soils, the temperature of solarized soil was always higher than the nonsolarized one with an average of 6oC at 8:00 AM and 14oC at 4:00 PM which resulted in a reduction in OM percentage. Both FMC and S addition had great effects on increasing soil EC compared to the increase that resulted from either solarization or SOB inoculation. The effect of elemental sulfur addition on decreasing soil pH was higher than the other treatments in clay soil, while FMC addition was the most effective treatment in sandy soil. The highest increase in available S was always found when soils were treated with elemental sulfur. Each of the treatments increased the available P in both soils, however the most effective treatment was FMC addition. Soluble Ca+2+Mg+2 and K+ were always increase due to each of the treatments. The highest increase in soluble Na+ was due to increasing soil temperature by solarization compared to the other treatments.

Two greenhouse pot experiments (clayey and sandy soil) were conducted in order to evaluate the effects of solarization (covering the soil with transparent plastic sheets), inoculation with sulfur oxidizing bacteria SOB (isolated thiobacillus), addition of filter mud cake (one of the sugar industry wastes, Nagaa Hammady Sugar Factory) as a source of organic matter and elemental sulfur (granule or micronize) on some sand and clay soil properties. In both soils, the temperature of solarized soil was always higher than the nonsolarized one with an average of 6oC at 8:00 AM and 14oC at 4:00 PM which resulted in a reduction in OM percentage. Both FMC and S addition had great effects on increasing soil EC compared to the increase that resulted from either solarization or SOB inoculation. The effect of elemental sulfur addition on decreasing soil pH was higher than the other treatments in clay soil, while FMC addition was the most effective treatment in sandy soil. The highest increase in available S was always found when soils were treated with elemental sulfur. Each of the treatments increased the available P in both soils, however the most effective treatment was FMC addition. Soluble Ca+2+Mg+2 and K+ were always increase due to each of the treatments. The highest increase in soluble Na+ was due to increasing soil temperature by solarization compared to the other treatments.