| Effect of tillage with stubble incorporated (TIS), no-tillage without stubble retention (NT), no-tillage with stubble standing (NTSS) and no-tillage with stubble retention (NTS) on yield and soil physical properties of winter wheat was studied by taking conventional tillage (T) as the control on a ten years'located experiment in Huangyang experimental station, Wuwei city, Gansu province. The main conclusions were showed as follow:1. Soil water content in 0-30cm layer in each growth stage was significantly increased in NTSS and NTS plots in comparison to that in T, TIS and NT plots under the same outside moisture conditions, the content in 0-30cm layer had significant changes among different measurement dates, that in 30-150cm layer kept stable, which indicated 0-30 soil body was the main body for moisture consumption of winter wheat in Hex irrigation region, while 30-150cm layer displayed a better effect on replenishment and equilibration for 0-30cm soil layer moisture, different tillage treatments had different effects on water content in winter wheat field. Soil water content in 0-30cm layer in NTSS and NTS plots in each growth stage was significantly higher than that in T, TIS and NT plots, while 30-150cm layer had no significant changes. Water content decreased from returning green stage to maturity under the same environmental factors.2. Soil bulk density of NTS, NTSS, NT and NIS was significantly lower than that of T in the measurement period, bulk density of NTS,1.30g/cm3, was the lowest among five treatments, NTSS took second place, both reached significant level in comparison to T, which indicated both NTSS and NTS could increased bulk density. Long term no-tillage with stubble retention could efficiently mitigate the increase of soil bulk density (0-30cm), soil compaction (0-20cm) was also decreased by T and TIS because of tillage and incorporating treatments, the mitigation was highlighted within returning green, jointing and booting stage. NTSS could significantly decrease soil compaction in 20-40cm layer. Soil compaction would increase after wheat harvesting while T, TIS, NT, NTSS and NTS significantly and NTSS, NTS not, in which soil compaction of NTS was lowest among five treatments, indicating soil compaction of NTS kept relatively stable by mitigating increase of compaction to promote stability of soil structure.3. Capillary porosity was effectively increased by NTS and NTSS, improving soil water retention and absorption as well as soil structure, in which NTS displayed better than NTSS. Total porosity was increased by NTS and NTSS, no-capillary porosity was also improved by NTSS in comparison to other treatments. Tillage treatments influenced soil temperature, soil temperature of T, TIS and NT was also higher than that of NTS and NTSS, the soil temperature of NTS and NTSS increased slowly, temperature difference was smaller from morning to night, having a significant effect of lowering temperature.4. Elastic-stable aggregate of NTS, NTSS, NT and NIS was improved in comparison to T, in which NTS was highest. Those treatments could also improve the content of soil aggregate within its particle size>5cm and 2-5cm. NTS, NTSS, NT and NIS could improve water-stable aggregate content, in which NTS and T reached significant level. NTS and NTSS could improve 1-0.5mm and 0.25-0.5mm. Water-stable aggregate content, indicating NTS could not only improve soil structure, but also ameliorate relative stableness and eternality of soil.5. Tillage treatments influenced yield and WUE of winter spring. NTS, NTSS, NT and TIS could improve wheat yield significantly, NTSS and NTS increased yield by 26.2% and 12.4%, respectively, in comparison to T, of which NTS outputted the highest yield. NTS, NTSS, NT and TIS could also improve WUE, NTSS and NTS increased by 19.6% and 12.6%, respectively, compared with T, of which NTS yielded highest WUE. NTS and NTSS could significantly improve soil organic matter in 0-10cm soil layer, while TIS 10-30cm soil layer. Organic matter of each treatment decreased from returning green to maturity stage, of which NTS's decreasing range was smallest, indicating the replenishment of organic matter was better than other treatments.
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