Abstract:In order to explore the effects of combination of conservation tillage and straw returning on water storage during fallow period, temporal and spatial variation of soil moisture during growth period, seasonal variation of water storage, yield and WUE of maize, the located experiment was conducted by setting 6 treatments of different tillage methods (no-tillage, sub-soiling and deep plowing) combined with straw returning (100% straw returning, no straw returning) in Jinzhong of Shanxi from 2016 to 2018. The results showed that:(1) The difference in soil water storage under different tillage treatments during spring maize winter fallow period was significant, and water storage had a decreasing trend along with time delay. The soil water storage of no-tillage and sub-soiling treatments increased by 10.4 mm and 9.3 mm, respectively, compared with deep plowing. During the whole growth stage of maize, the soil water storage of no-tillage and sub-soiling was 4.8% and 1.2% higher than that of deep plowing. (2) The order of average soil water content for two years was no-tillage > sub-soiling > deep plowing, the average soil water content of each treatment was 23.0%, 21.8% and 21.5%, respectively. The vertical variation of soil water content under different tillage methods varied greatly during different growth periods in wet year, and while the variation in drought year was small. (3) The combination of no-tillage and 100% straw returning had the highest yield and WUE of maize, the 2-year average yield and WUE was 12 679.9 kg/hm2 and 25.8 kg/(hm2·mm), respectively. The combination of deep plowing and 100% straw returning had the lowest yield and WUE. Regardless of whether straw was returned to the field or not, no tillage and sub-soiling were better than deep plowing on soil water conservation in winter fallow period, soil moisture status in growth period, yield and WUE of spring maize. No-tillage and sub-soiling tillage under straw returning had good effect on water collection and conservation in maize field. The combination of no-tillage and 100% straw returning had the best effect, it could be promoted and applied in spring maize production in Jinzhong area.