R eCeNt fertilization strategies in the world show that the use of environment safe fertilizers is of great importance to decrease the harmful effects of fertilizers on environment and human health, especially in the newly reclaimed soils. therefore, this study was carried out to evaluate the effect of some environmental safe fertilizers (i.e., organic and bio fertilizers) in different sources on sandy soil productivity of peanut plants (Arachis hypogaea L.). the used organic fertilizers were farmyard manure (FYM), solid plant compost (SPC), enriched compost tea with humic substances (eCt) and mixture of FYM and eCt, while the used bio-fertilizers were B1 (Azospirillum braselinse+ Bacillus megatherium + Azotobacter chroococcum) and B2 (Bradyrhizobium sp. USDA 3456+ Serratia marcescens MH6+ Psuedomonas fluorescens IFO 2034. the obtained data showed the superior increase effect of eCt followed by FYM+eCt applications straw, pods and seed yields straw and seeds contents of N, P and K as well as seeds contents of protein and oil. Similar increase for all determined parameters were found in the plants inoculated by B2 compared to that with B1. thus, use of both organic and bio-fertilizers in the fertilization strategy of sandy soil is very important and also may be economically.

Water is essential to the existence of human and all living things. Groundwater occurs almost everywhere beneath the earth surface not only in a single widespread aquifer, but also in thousands of local aquifer systems. Man's activities such as food production and nutrition are dependent on water availability in adequate quantities and good quality (Howari et al., 2005). Water is the most common and widespread chemical compound in nature which is a T MANAL F. TANTAWY et al.

This laboratory experiment was carried out to study the individual and combined effect of two organic acids (humic and oxalic acids) and salinity levels of irrigation water on the changes of chemical properties and the content of available phosphorus of two calcareous soils of Egypt. The soils were treated by either humic or oxalic acid at application rates of 0, 0.1, 0,2 and 0.4% and irrigated by one of irrigation water resources varied in their salinity levels at 100% of soil field capacity. The used three water resources were tap water (W1), sea water (W3) and mixed water between W1 and W3 with mixed ratio of 1:1 (W2). This experiment was carried out in plastic pots, where it arranged in completely block randomized system with three replicates. These pots were incubated at room temperature (25 ± 2 • C)for 6 months. After that, soil pH, EC (dSm-1), CEC (meq/100g), total and active CaCO3 (%) and the content of available P (mg/kg) were determined. Organic acids applications resulted in a decrease of soil pH and its content of total CaCO3 % and increased soil EC (dSm-1), CEC (meq/100g), and the content of active CaCO3 (%) and available P (mg/kg). On the other hand, increasing salinity levels of irrigation water resulted in a decrease of soil content of total CaCO3 and increased soil pH, EC, CEC, active CaCO3 and available P. The relative changes (RC, %) of the studied soil properties were varied widely from soil to anther depending on type and application rate of the used organic acids and salinity level of irrigation water.

Thirty surface and subsurface soil samples were collected from 15 sites of El-Dakhla soils, Egypt to study the status of soil potassium forms and their relationship with the physical and chemical properties of these soils. The results indicated that the investigated soil samples showed a wide variation in soil potassium forms. This variation depended upon clay, silt and sand contents as well as soil properties. The soluble K form values ranged from 4.7 to 1332 mg/kg and the exchangeable K form differed from 5.37 to 1368.80 mg/kg. However, the non-exchangeable K form varied from 0.3 to 4.2 g/kg and the total K varied from 2.3 to 19.89 g/kg. The residual K extended from 0.9 to 17.4 g/kg. Generally, about 16.66 % of studied samples were very low in the exchangeable K form. The samples which had a moderate exchangeable K content represented 13.33% of the investigated samples. Also, about 20% of these samples were high in their content of exchangeable K. The very high exchangeable K content represented 40% of the investigated samples. The ECe value had no respectable effects on the soluble K form but, a slight effect was observed in the other K forms. This effect increased in the residual K form. The OM content more than 1% had no remarkable effects on the soluble or exchangeable K forms. However, a clear effect was observed on the residual K form. Generally, all potassium forms had highly significant positive correlations with each other and with organic matter and pH. Also, all forms except the soluble K form showed highly significant negative correlations with calcium carbonates and sand content.

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