IMPROVEMENT OF CERTAIN HEAVY ELEMENTS STATUS IN SALT- AFFECTED SOIL IRRIGATED WITH LOW QUALITY WATER

Wastewater, mostly without pretreatment, has been used for
irrigation in some locations such as Bahr El-Baqar drain area in El-
Hosinia plain, Sharkia Governorate. A survey study including
wastewater, soil and plant was carried out in El-Hosinia area to
identify such problem. Moreover, certain amendments i.e. gypsum,
byproduct rich in Ca from citric acid company (BCC) and citric acid,
were applied to contaminated studied soil columns experiment to
assess their effects on the distribution of Fe and Mn among the
different soil fractions as well as the bioavailability of certain heavy
elements, consequently their contents in cotton seeds.
The obtained results showed that Bahr El-Baqar drain water was
contaminated with Fe, Mn, Zn, Cu, Pb, Ni, Co and Cd which were
higher than exceeded the permissible limits, while roots of alfalfa and
rice plants grown on such soil contained Fe and Mn,as well as plants
shoots contained only Fe , above the normal range.
Soil Fe fractions were in the following order: residual fraction>
reducible bound> organically bound> carbonate fraction>
exchangeable Fe, but Mn fractions were in the following order:
reducible bound> residual fraction> carbonate fraction> organically
bound> exchangeable Mn. The applied treatments increased the
downward movement of Fe and Mn as indicated by increasing their
concentrations with increasing soil depth and this point out to the
possibility of reducing such heavy elements concentration at plant root
zone. Gypsum amendment was superior in reducing the chemically
available Fe and Mn followed by byproduct (BCC). Heavy elements
IMPROVEMENT OF CERTAIN HEAVY ELEMENTS STATUS238
content in seeds of cotton plants cultivated in soil columns were
within the sufficient range