TOTAL AND PLANT AVAILABLE CONTENTS OF COPPER AND ZINC IN URBAN CULTIVATED RICE FARMLANDS

Forty composite samples from eight cultivated rice farmlands were collected and analyzed for both total and plant available Copper and Zinc using Atomic Absorption Spectrophotometric technique. Some physico-chemical parameters of the soil samples were determined; for the pH all the analyzed soil samples revealed different ranges of acidity and the organic carbon contents ranged from 0.46 to 1.4%. Varying contents of Cu and Zn were obtained; the overall total Cu and Zn mean values were 9.8 and 35.8 mg/kg respectively, while the plant available Cu and Zn had mean concentrations of 3.5 and 8.5 mg/kg respectively. The overall order of relative availability in the studied soils revealed that Cu was extracted in the highest relative amount than Zn and the geo accumulation index revealed that the studied soil samples were uncontaminated to moderately contaminated. Hence, the need for further constant monitoring of the levels of heavy metals in cultivated rice farm lands because of the persistent applications of fertilizers as well as other agricultural chemicals and their possible consequence effect on the food chain.