In order to investigate the effects of different sand-gravel mulching amounts on soil water movement

soil water storage

evapotranspiration processes and winter wheat growths

two-year experiments were conducted in 24 soil containers which were put under a rain shelter at four sand-gravel mulching amounts (0

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46 and 69 kg/m2). The soil water dynamic change was observed by a micro-lysimeter which contained a high-precision weighing transducer connected with a data logger. For the no-wheat and with-wheat conditions

when the sand-gravel mulch amounts increased from 0 to 69 kg/m2

the treatments were named NW0

NW23

NW46

NW69 and W0

W23

W46

W69

respectively. The results showed that: (1) Soil water storage increased with the increase of sand-gravel mulch amounts

the monthly soil evaporation

monthly evapotranspiration

cumulative soil evaporation and cumulative evapotranspiration decreased with the increase of sand-gravel mulch amounts. Soil water storages under the with-wheat conditions were lower than the values of the no-wheat conditions. The monthly soil evaporation

monthly evapotranspiration

cumulative soil evaporation and cumulative evapotranspiration under the with-wheat conditions were a little bit higher than the values under the no-wheat conditions

especially at the later winter wheat growth stages. Under the no-wheat conditions

in the first and second years

the total evaporations of the three coverage treatments were less than the non mulching treatment from 11.6% to 18.1% and 28.5% to 47.5%

respectively. Under the with-wheat conditions

in the first and second years

the total evapotranspiration of the three coverage treatments was less than the non mulching treatment from 2.2% to 3.7% and 0.7% to 3.6%

respectively. (2) All of the plant heights

leaf area indexes

productive panicle number

yields and water use efficiencies of the winter wheat increased with the increase of sand-gravel mulching amounts. In the first and second years

the maximum plant height of the three coverage treatments was more than the non mulching treatment from 5.3% to 17.2% and 1.0% to 5.8%

respectively. The maximum leaf area index of the three coverage treatments was more than the non mulching treatment from 17.9% to 74.6% and 7.9% to 28.2%

respectively. The yields of the three coverage treatments were more than the non mulching treatment from 6.6% to 14.2% and 12.6% to 44.6%

respectively. The water use efficiency of the three coverage treatments were more than the non mulching treatment from 8.0% to 16.1% and 15.6% to 67.1%

respectively. From the results

the most suitable sand-gravel mulching amount was 69 kg/m2

the sand-gravel mulch can effectively prevent soil water evaporation

the increased soil water storage at early crop growth stages could be utilized for later stages of crop growth

which highly contributes for improving crop yields and water use efficiency.