4.1. Physical and chemical properties
Our results for the CGCC- and PM-amended soils showed that the added organic matter increased the soil structural
stability, especially at high organic waste doses and at the end of the experimental period. This was in agreement with those of Chenu et al. (2000), Puget et al. (2000) and Tejada and Gonzalez (2003, 2004) who found that a good soil structure depended on the content and nature of the organic matter added. This organic matter promotes flocculation of clay minerals, which is an essential condition for the aggregation of soil particles. The increase in structural stability was especially evident in CGCC amended soils at the end of experimental period and this was probably due to different chemical composition of the wastes used. This difference is evident from the different concentrations of humic and fulvic acids.