Effect of land use on some heavy metals in the newly reclaimed soils of el-Sharkeya governorate

الملخص EN

IGHT soil profiles representing the newly reclaimed soils of El-Khattara, El-Sharkeya Governorate were selected to study the effect of land use period on both the total and DTPA-extractable contents of Fe, Cu, Pb and Cd.

The selected profiles covered a wide range of land use periods, i.e., virgin soil and cultivated to 7, 10 and 14 years.

The relationships between the different soil parameters and both the total and DTPA-extractable contents of the studied elements were also examined The results indicate that under virgin condition, the average total content was 1770.0, 3.73, 3.87 and 0.036 mg / kg for Fe, Cu, Pb and Cd, respectively.

In the soil cultivated for 7, 10 and 14 years, the average total content was 1978.0, 2049.0 and 2116.0 mg / kg for Fe; 6.669, 7.04 and 8.205 mg / kg for Cu; 2.640, 1.482 and 2.329 mg / kg for Pb and 0.605, 0.545 and 0.402 mg / kg for Cd, respectively.

Data show that the DTPA-extractable content for the studied elements differed widely between the different periods.

Under virgin condition, the DTPA extractable content averaged at 3.615, 0.495, 0.785 and 0,001 mg/kg for Fe, Cu, Pb and Cd, respectively.

In the cultivated soil for 7, 10 and 14 years, the average content was 2.493, 2.863 and 4.668 mg / kg for Fe, 0.744, 0.320 and 0.600 mg / kg for Cu, 0.175, 0.229 and 0.245 mg / kg for Pb and 0.002, 0.012 and 0.017 mg / kg for Cd, respectively.

Applying statistical measures dictates that the weighted mean variations may be ascribed to the parent material itself rather than soil formation or local conditions.

The values of the trend for total Fe and Cu and chemically extractable Cu and Pb indicate their highly symmetrical distribution with less symmetrical distribution of the other elements.

The specific range variations are mainly attributed to pyogenic processes, sedimentation regime and local conditions.