Effect of basic slag addition on soil properties, growth and leaf mineral composition of beans in a Cu-contaminated soil

International audienceBasic slag (BS) is an alkaline by-product of the steel industry with potential properties to ameliorate nutrient supply and metal stabilisation in contaminated soils. The BS effects on soil pH, soil conductivity, growth and chemical composition of beans were investigated using an acid, sandy soil from a wood treatment facility containing 630 mg Cu kg-1. Pot experiments were carried out on a 2-week period with Phaseolus vulgaris L. An uncontaminated, sandy soil was used as a control (CTRL). BS was added into the soil (1 kg soil pot-1) to constitute four treatments in triplicates: 0 % (T1), 1 % (T2), 2 % (T3) and 4 % (T4) BS kg-1 air-dried soil. The BS addition increased soil pH, soil conductivity, and plant growth compared to the untreated soil. At 1 % and 2 % BS addition rate, highest shoot yields (dry weight, DW) occurred. Foliar Cu concentration varied from 5.6 mg kg-1 to 53.1 mg kg-1 in the following order: CTRL < T2, T3, T4 < T1. The highest decrease in the foliar Cu concentration, 2.3 times compared to T1 plants, was obtained for the T2 plants. The BS addition at 1% rate into the Cu-contaminated soil promoted bean growth with the lowest foliar Cu concentration. Foliar Ca concentration was enhanced in the T2, T3 and T4 treatments whereas the foliar P concentration was not promoted