Soil quality research differs from some soil management research in that it emphasizes the multifaceted nature of soils and requires that physical, chemical, and biological aspects of the soil be considered simultaneously. Unsupervised methods of multivariate statistics are powerful tools for this integrated assessment and can help soil researchers to extract much more information from their data. In our study, soil quality indicator is constructed by divers measured properties by this technique. Soil quality was assessed on a set of 20 plots submitted to different types of land use, tea plantations with diverse degrees of intensification and fertilizer, orange tree plantation, sugarcane, bamboo forest, pine forest and wasteland in the region of Yingde (Guangdong Province, South China). Our study aimed to design a synthetic indicator that allowed quantifying the physical state, chemical fertility, quality and stocks of organic matter, aggregation and morphology in the surface soil (0 - 5 cm) and diversity and composition of soil macroinvertebrate communities. These 5 sub-indicators (physical, chemical, organic matter, morphological and biodiversity) then are combined into a general index. Significant differences were observed among different plantations and tea plantations with different history and managements by general indicator of soil quality (GISQ). Tea plantations that were replanted and with less residue had lower GISQ than plots that had not been replanted, more residue and manure was applied. Tea plantations with urea had lower GISQ than plots applied manure. Orange plantation with fertilizers of manure, lime and N, P, K had the maximum GISQ. Compared with mineral fertilizers or pesticides, use manures or organic residues could improve soil quality, control pests naturally, improve soil C circulation. Soil morphology sub-indicator seems to be affected greatly by the type of fertilizers applied. Soil organic matter status is observed to be the crucial factor that determines soil quality, which favors the presence of invertebrate, improves it's abundance and biodiversity; this results in more biogenic aggregates that are created by invertebrate. Chemical sub-indicator is very sensitive to manure, fertilizer and lime.application. On the contrary, physical sub-indicator is less dependent on differences of fertilizer application, it is the clay content that most differs the sites.
