Status of some trace elements and heavy metals in the soils of dakhla oasis, western desert, Egypt : 1. Trace Elements

الملخص EN

The soils of West El-Godiva, Dacha Oasis (between latitudes 25o 33` and 25o 39` N and longitude 28o 40` and 28o 46` E) represent 43560 sedan.

These soils were investigated to assess their contents of Fe, Mn, Zn and Cu.

A total of 36 samples representing 9 virgin and cultivated soil profiles were grouped into three soil groups, namely : coarse 1 to moderately coarse-textured soils, represented by profiles 2 and 3; moderately fine to fine-textured soils with coarse surface represented by profiles 4, 5 and 6 and moderately fine to fine–textured soils represented by profiles 7, 8 and 9.

Soils samples were analyzed for their physical and chemical properties.

Total and DTPA-extractable contents of the studied elements were also determined.

These soils are of variable texture (coarse sand to clay), having low contents of CaCO3 and organic matter.

Most soils were saline having EC of paste extract exceeding 4.0 dSm-1.

The mean total content of the studied elements in the different soil groups ranged from 7470.7 to 8476.25, 250.89 to 399.48, 18.49 to 29.88 and 7.

73 to 14.42 mgkg-1 for Fe, Mn, Zn and Cu, respectively.

The lowest means for Fe and Mn and Zn and Cu were recorded in the soils related to the coarse to moderately coarse-textured soils and moderately fine to fine textured soils, respectively, while the highest means for Fe and Mn and Zn and Cu were related to the moderately fine to fine–textured soils with coarse surface and coarse to moderately coarse-textured soils, respectively.

The mean DTPA-extractable content of the studied elements ranged from 3.50 to 4.84, 3.05 to 16.56, 0.42 to 0.48 and 0.31 to 40.4 mg kg-1 for Fe, Mn, Zn and Cu, for the three groups, respectively.

The lowest means for Mn and Cu ; Fe and Zn were recorded in the soil groups : coarse to moderately coarse-textured soils, moderately fine to fine-textured soils with coarse surface and moderately fine to fine–textured soils, respectively, while the highest mean for Fe and Mn, Zn and Cu was related to moderately fine to fine–textured soils, coarse to moderately coarse-textured soils and moderately fine to fine–textured soils with coarse surface, respectively.