Effects of some industrial and organic wastes application on growth and heavy metal uptake by tomato (Lycopersicum esculentum) grown in a greenhouse condition.

Abstract

In this study, pot experiments were conducted to determine the effects of industrial solid wastes (ISWs) (ceramic, stone, and sugar factory wastes) and organic wastes (rice husk and wheat straw) on growth and heavy metals uptake by tomato (Lycopersicum esculentum) plants. The soil was treated with 10% of ISWs and 5% of organic wastes. The fractionation of heavy metals also has been studied in all treated soils. It was observed that the addition of ISWs in soil increased heavy metal contents in all fractions. The addition of organic wastes to control and treated soils decreased exchangeable fraction and increased organic matter and residual fractions. Following the ceramic factory and stone cutting waste addition, tomato yield significantly decreased as compared to control soil. The application of ISWs caused an increase in heavy metal contents of tomato plants. In control and ISWs-treated soils, dry matter yield of tomato grown in the presence of wheat straw was significantly restricted, while the application of rice husk increased tomato shoot and root dry weight. Results of experiments indicated that the application of both organic wastes significantly decreased heavy metal uptake by tomato plants. The investigation of health risk index (HRI) values indicated that in these industrial areas, potential health risk by intake of heavy metals from tomato for both adults and children generally assumed to be safe. The values of HRI were lesser when rice husk was applied to the soil. In general, these results highlighted that the application of rice husk in soils contaminated with ISWs increased the growth and yield of tomato and reduced the heavy metal toxicity for tomato consumption in contaminated soils.