Cement Kiln Dust (CKD), a by-product dust, is generated in large quantities during the manufacture of the cement. The fine particles of dust can be inhaled along with air and cause pollution to the soil around the cement factories. El-Minia Governorate, Egypt contains two cement factories. The first produces the white cement and the second produces the black cement. To environmentally monitor the soil pollution in the two studied areas, soil sampling was carried out in the Northern, Southern, Eastern, and Western directions around each cement factory. Soil samples were taken at six different monitoring distances away from each cement factory which are: 50m, 100m, 500m, 1km, 5km, and 10km. The values of EC, PH, Pb, Ni, and Cd of each site of the studied four directions around the two cement factories were decreased by increasing the monitoring distance from 50m up to 10km away from each studied cement factory. The electrical conductivity values of the top soil of the monitoring points were ranged between non-saline and very slightly saline. The PH values of the top soil of the monitoring points were ranged between neutral and moderately alkaline. The values of lead, nickel, and cadmium of the top soil of the monitoring points were below the allowable concentrations in the arable soil. This indicated that concentration of lead, nickel, and cadmium in the top soil around the two cement factories still in a safe level.

Many researchers worldwide have suggested the use of cement kiln dust (CKD) as a soil amendment and a source of nutrients to enhance crop performance. Pot experiment was accomplished in the greenhouse of Soil Science Department, Faculty of Agriculture, Minia University, to investigate impacts of white and black CKDs applied at six rates (0, 4, 8, 12, 16, and 20 g kg -1 ) to sandy loam soil on some soil chemical and biological properties and maize growth and quality parameters. Treated soils with either white CKD or black CKD were very slightly saline; moderately alkaline; and still in a safe lead, nickel, and cadmium levels. Soil amendment by increasing white CKD rate from 0.0 up to 16 g kg -1 increased microbial biomass C and N and enzyme activity of arginase and β-glucosidase. The highest values of plant height, fresh and dry weight of maize plants, and water use productivity by maize plants were recorded with 16 g kg -1 of white CKD. There was no distinct accumulation of lead, nickel, and cadmium in the maize shoots. It is applicable to use white CKD only at the application rate of 16 g kg -1 (16 Mg feddan -1 ) for crops grown in sandy soils under conditions of El-Minia Governorate, Egypt.

Agronomic use of cement kiln dust (CKD) improves sandy soil properties and promotes growth and development of plants to enhance crop yield. Field experiments were carried out on a private farm at a newly reclaimed land in the Western district of Nile valley, El-Minia Governorate, Egypt. The aim of this study was to investigate effects of white and black cement kiln dusts applied at six rates (0, 4, 8, 12, 16, and 20 Mg feddan -1 ) to sandy loam soil on some soil chemical properties, growth, yield, and heavy metals uptake of lead, nickel and cadmium by wheat and fodder sorghum plants. The results indicated that white and black CKDs are considered to be safe by-product materials in terms of pH and content of lead, nickel, and cadmium, however; they are potentially hazard in terms of salinity build up in the investigated soil. Heavy metals concentration in the investigated soil was in the following descending order: Lead > Nickel > Cadmium. The investigated soil remains at a safe level of lead and nickel, while in a potential level of unsafe cadmium. The highest value of wheat yield and fodder sorghum was recorded when white CKD was applied at the rate of 16 Mg feddan -1 . From these results, it could be recommended to apply white CKD at an application rate of 16 Mg feddan -1 only once for common crops cultivated in sandy soils under conditions of El-Minia Governorate, Egypt.

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Content of Cu, Zn, Fe, Mn, and Pb, their mobility and their specific binding to soil constituents of sandy and alluvial soils of Egypt were measured according to a sequential extraction scheme. The results showed that, total contents of these metals were higher in alluvial soils than in sandy desert soils. In contrast, no or less differences were found in the mobile and easy mobilisable fractions of both soil types. At least the same amounts of heavy metals were available to plants. In sandy and alluvial soils most of Cu and Zn were bound to silicates. In the soils with high carbonate contents considerable part of these two elements were carbonatic bound and not easily available. In alluvial soils most of Cu, Zn and Pb were mainly organically bound, however, in sandy soils most Pb was measured in the residual fraction.For most of the studied metals, the relative distribution of the various chemical fractions in the alluvial soils descended as follows: organically bounded > oxide occluded >bound to lime > easily mobilisable > soluble + exchangeable, while in desert sandy soils it was in the following order: oxide occluded > bound to lime > easily mobilisable > organically bounded > soluble + exchangeable.

Two pot experiments were conducted during two successive seasons of 1998 and 1999 to evaluate the influence of sewage sludge applied to sandy calcareous soils on physical and chemical properties of the soil, plant growth, dry matter yield, water consumption, water use efficiency, elemental content as well as uptake of N, P, K and Pb by Casuarina equistifolia seedlings which used as windbreaks and wooden trees.The studied soil was treated by different rates of sewage sludge namely, 0, 1, 2, 3, 4, 5 and 6%. The changes in chemical properties of the treated soil before and after cultivation were measured. Also, the soil content of total N, available P, K and DTPA Pb was determined after cultivation.The obtained results showed that application of sewage sludge to sandy calcareous soils, improved hydro-physical and chemical properties of the soil.. Plant growth, dry matter yield, water use efficiency, concentration and uptake of N, P, K and Pb by plants were increased.The rate of increase percent in different treatments for NPK uptake by plants relative to control (100%) were 394.3%, 353.1%, 249.5% and 390.2%, 431.9%, 306.9% in the two successive seasons, respectively.The results showed that the application of sewage sludge to newly reclaimed sandy soil improved soil chemical properties before and after cultivation and nutrients status of the soil after cultivation.The most outstanding beneficial effect was obtained as a result of adding sewage sludge to sandy calcareous soils at the rate of 4% (40 ton/fed). So, one can conclude that sewage sludge can be considered as a good soil conditioner for improving coarse textured soils properties and planting wooden trees in the desert as windbreaks and as a source of wood production.