The rain fallen after 140 days from the beginning of the test saturated the soil S1, causing the first release of leachate. This event is clearly identifiable in the highest peaks of volume graph in Fig. 3 (upper left), as well as in all graphs of S1 of the same figure showing the monitored substances (i.e., potassium, polyphenols, nitrate). Although before the saturation of S1 the volume leached through the two soils was substantially different, as expected, after the saturation the various treatments yielded similar trends for both soils.