ABSTRACT
Irrigation of Abu-Rawash area, Giza, Egypt with primary-treated wastewater for 50 years caused accumulation of heavy metals. The area was divided into the following 5 different categories according to the duration period of irrigation 0, 10, 20, 25 and 50 years. Analysis of available N, P, K, Cu, Zn, Fe and Mn nutrients and Pb, Ni, Mo, Cd, and B heavy metals were done on soil samples from layers of 0-30, 30-50 and 50-100-cm. Salinity was highest in the uncultivated soil than in the cultivated ones. With increase of years of cultivation, the contents of nutrients and elements were greater. The contents of nutrients and elements in the surface exceeded those of the subsurface. Ranges of available contents of elements (mg kg-1) in the top soil layer were 8 – 456.7(N), 5.5 - 138(P), 88 - 1190(K), 1.5 -16(Cu), 4 - 18(Zn), 4.7 – 80.6(Fe), 0.08-0.54(B), and 2 - 30(Mn). Respective ranges in the deepest layer were 1.6 – 16.9(N), 2.9 – 46.52(P), 27 – 83.6(K), 0.7 – 1.3(Cu), 1.3 -5.5(Zn), 1.9 – 18.24(Fe), 0.05-0.08 (B) and 0.9 – 4.8(Mn). After 50 years of irrigation with wastewater heavy metals of Pb, Ni, Mo, and Cd in the top layer showed a descending order with values of 10.81>2.22>0.23>0.16 respectively. In the deepest layers the contents were 0.29>0..05> 0.00=0.00, respectively.
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