INFLUENCE OF CHROMIC IONS IN MAIZE CULTIVATION (ZEA MAYS) AFTER THE ADDITION OF NATURAL MINERALS AS SOIL AMENDMENTS

摘要

The present study examines the efficiency of natural materials regarding the retention of trivalent and hexavalent chromium, from maize (Zea Mays). The natural materials that have been used as soil amendments were zeolite, bentonite and goethite. Specifically, 1.0 kg of soil and 1.0 g of each soil amendment were added in plant pots. Two doses of chromic ions, i.e. 50 mg Cr(III) L~(-1) in the form of Cr(NO_3)_3 or 1 mg Cr(VI) L~(-1) in the form of CrO_3 were added to plant pots. Then, plant seeds of maize crops were cultivated. Five treatments were realized for each dose of chromic ions (5 x 2) but only three contained soil amendment. Each treatment was repeated three times. The statistical results of the greenhouse experiments were analyzed by LSD test with significance 95% (p<0.05) using Stratgraphics Plus 8.1 package. According to the results, the addition of trivalent chromium in soil has shown that zeolite was the only soil amendment that increased the dry weight of biomass. Zeolite and bentonite as soil amendments reduced significantly the total chromium in plants compared to all the other treatments after the addition of 50 mg Cr(lll) L~(-1) to soil. The addition of hexavalent chromium in soil has shown that bentonite was the only soil amendment that increased the dry weight of biomass and the plants' height. All soil amendments reduced to zero the total chromium concentration measured to plants after the addition of 1 mg Cr(VI) L~(-1) to soil.