Previous studies suggest that the degree of rainfall infiltration and soil water evaporation differs according
to the amounts of straw mulch used in mulching treatments and that the soil water-holding capacity
differs with various mulching treatments11,26. Throughout our three-year study, we found that irrespective
of the fallow period rainfall rate, the water storage status improved to varying degrees with the straw
mulch treatments compared with CK. This improvement probably occurred because crop straw can disconnect
the evaporation surface from the capillarity of the subsoil, thereby greatly inhibiting soil water
evaporation, which significantly improves the soil water condition1,27. However, the water storage level
was not consistent in both years with all of the mulch treatments, i.e., the levels were lower in 2008-2010
compared with those in 2007-2008 when the amount of rainfall was reduced. Straw mulch is known to
be an effective practice that promotes water conservation by reducing soil water evaporation during the
summer fallow period17, which increases crop yields27. Deng et al.28 reported that in a dryland farmland
area in Northern China, the precipitation during the wheat growth period only accounted for 65%–95%
of the actual water consumption and 5%–35% of the consumed water was obtained from the soil water
stored before sowing. In our study, we showed that the whole-period mulch treatments facilitated more
effective storage of summer rainfall in the soil, thereby increasing the soil water storage and rainfall