Abstract:In order to investigate the effect of autumn tillage on the regulation of seasonal freeze-thaw soil thermal conditions, this study compared and analyzed the effects of the five treatments:Traditional tillage (FG), no-tillage (MG), ridge-furrow (LG), tillage followed by activated carbon mulching (FH), and tillage followed by straw mulching (FJ), on soil temperature, freeze-thaw cycles and soil temperature gradients. The results showed that compared with the FG, MG, LG, FH and FJ treatments all weakened the correlation between soil temperature and air temperature, reduced the dynamic magnitude of soil temperature throughout the freeze-thaw period and the degree of diurnal variability of soil temperature at different freeze-thaw stages, and maintained the stability of the soil temperature sequence as FJ > FH > LG > MG. The FG was the first to freeze and melt, and the remaining treatments delayed the effect of soil freezing and melting rate as FJ > FH > LG > MG. And the smaller the freezing and melting rates, the more frequent the freeze-thaw alternation and the greater the number of freeze-thaw cycles. The soil temperature gradient of all treatments showed a highly significant correlation with air temperature (P < 0.01), and the degree of correlation was FG > LG > MG > FH > FJ. All treatments showed a highly significantly negative correlation with soil water storage (P < 0.01), and the degree of correlation was FJ > FH > LG > MG > FG. MG, LG, FH, and FJ treatments all enhanced the retention of soil water and heat resources, in which FJ and FH promoted the upward movement of deep soil heat, which was more conducive to improving soil water and heat conditions during seasonal freezing and thawing and maintaining soil moisture in spring sowing in the north Xinjiang.