Objective: The objective of this article was to evaluate the soil quality under different mechanical tillage treatments: no-till with straw-mulching (SM), no-tillage (NT), film-mulching (FM), conventional tillage (CT), in the southern edge of Mu Us desert. Method: Based on results obtained from an experiment of six years, 13 soil fertility indexes were selected and grouped into three common factors using factor analysis method: the potential fertilizer factor F1, organic matter factor F2, biological activity factor F3, and calculated scores of all measures were comprehensive and crop yields were used to verify the evaluation results. Result: The results showed that: (1) The score trend of soil fertility quality under different tillages was film-mulching > no-tillage=conventional tillage > no-till with straw-mulching, which was basically consistent with yield trend film-mulching > conventional tillage > no-tillage > no-till with straw-mulching, indicating evaluation results were reliable and valid. (2) Owing to microbes under straw mulching treatment consuming a large amount of nutrients, three common factors had lower scores and soil fertility quality score was the lowest in the no-till with straw-mulching treatment; The highest soil organic matter factor score in the no-tillage treatment indicated that the no-tillage measure was conducive to the accumulation of soil organic matter; The highest soil potential fertility factor score but lower soil organic matter factor score in the conventional tillage measure indicated that the conventional tillage measure was not conducive to the accumulation of soil organic matter, and cannot be the best treatment for sustainable agricultural development; The highest biological activity score but the lowest soil potential fertility factor score in the film-mulching treatment indicated that the FM treatment was conducive to the effectuate of potential soil nutrient. Conclusion: Factor analysis method could better reflect quality of soil fertility and could be used for soil quality evaluation.
