Effects of the incorporation of biosolids on soil quality: temporal evolution in a degraded inceptisol (typic endoaquepts)

Abstract

The purpose of this study was to determine the temporal evolution of soil properties following the incorporation of biosolids in a degraded Inceptisol soil (Typic Endoaquepts). The study was conducted in the Araucania Region of Chile, where two sampling zones were established: a control zone without biosolid incorporation and a zone with biosolid incorporation. Experimental field plots were used to measure soil quality, including soil respiration (SR), infiltration (IN) and bulk density (BD), according to standard USDA methodology. Laboratory analyses of soil chemistry, including pH, electrical conductivity (EC), organic matter (OM), nitrogen (N), aluminium (Al), phosphorus (P) and sulphur (S), were performed using the analytical techniques of the Chilean Society of Soil Science’s CNA. Measurements were performed 17, 170, 365 and 510 days after the biosolids were applied. The results indicated significant changes in soil quality 1.4 years after the incorporation of the activated sludge, particularly in sustained increases of phosphorus content, soil respiration and infiltration. In addition, there was a significant increase in the electrical conductivity of the soil, which ranged from normal to high.