Ion leaching and soil solution acidification in a vadose zone under soil treated with sewage sludge for agriculture.

In this study, we performed monitoring of the soil solution (SS) over 10 years on a loamy/clayey-textured Dark Red Dystroferric Oxisol that received sewage sludge for agricultural purposes. The SS was obtained by lysimeters installed along the walls of a well at 1 m, 2 m, 3 m, 4 m and 5 m in depth. The major ions found in the SS were NO, SO, Cl, Ca, Mg, Al, Pb, Cd and Zn, and the pH level ranged from 4 to 6.