Fig. 1. Schematic diagram of one segmented soil column. Leachate was moved through the soil using a mechanical vacuum extractor at a flow rate of 38 mm h^-1. Leaching was conducted by alternating six times a) leaching of 40 mL of solution sequentially through all three segments and b) leaching of three 5-mL batches (i) through the surface soil segment only, (ii) through the surface soil segment and then through the first subsoil segment, and (iii) through all three segments. In the second experiment nine consecutive batches of 40 mL were sequentially leached through all three segments before compost was added and the 40-mL leaching and 5-mL sampling scheme was performed.