The influence of rotational tillage on soil water storage, water use efficiency and maize yield in semi-arid areas under varied rainfall conditions

•The implementation of conservation tillage practices during fallow period could store water for spring-sown crop.•Rotational tillage showed superiority in soil water than single tillage practice, but the efficiency varied under different rainfall conditions.•Grain yield gaps under different rainfall totals, distribution and tillage practices were mainly due to differences in number of kernels per ear.•Rotational tillage practices could increase grain yield and WUE in dry years and close the yield gap during normal rainfall years.