In order to explore the suitable tillage systems in dryland for high efficiency wheat production in Jinnan,four systems,including DT/DT (2-year continuous deep plowing during fallow period),ST/DT (2-year rotational subsoiling and deep plowing during fallow period),ST/ST (2-year continuous subsoiling during fallow period) and CK (2-year continuous conventional tillage system during fallow period) were applied.The study was conducted with Jinmai 92 to determine the effect of different tillage systems on soil water storage and nutrient content,crop growth and water use efficiency.The results showed that compared with CK,DT/DT,ST/DT and ST/ST significantly increased soil water storage in the 0-3 m depth after fallow period and soil water storage efficiency.And soil water storage efficiency was increased by 52.5% to 91.3%.The effect of ST/ST on water storage was better.Compared with CK,DT/DT,ST/DT and ST/ST increased soil water storage in the 0-3 m depth from over-wintering stage to booting stage,on which the effect of ST/ST was significant.Compared with CK,DT/DT,ST/DT and ST/ST increased dry weight per plant at different growth stages.Compared ST/ST and ST/DT with CK from over-wintering stage to elongation stage,the effect was significant.And the effect of different tillage systems was significant at booting and maturing stages.Compared with CK,DT/DT,ST/DT and ST/ST significantly increased spike number,1 000-grain weight,yield and water use efficiency.Spike number,water use efficiency and yield were increased by 22.7% to 29.9%,15.1% to 21.6%,and 39.4% to 60.3%,respectively,on which the effects of ST/ST were better.Compared with CK,DT/DT,ST/DT and ST/ST improved soil average nutrient content in 0-40 cm depth after harvest.Organic matter content,available phosphorus content and alkali-hydrolyzable nitrogen content were improved by 2.5% to 8.7%,11.1% to 34.4%,and 5.1% to 20.2%,respectively,on which the effect of ST/ST was better.In conclusion,DT/DT,ST/DT and ST/ST could improve soil water storage capacity and soil nutrient supply status,and promote the accumulation of wheat matter,which was favorable for improving grain yield and water use efficiency.The ST/ST system was optimal. |