: (1) flat gravel–sand mulched field, (2) RFRHS with a sand mulched furrow, entire plastic mulch and the ratio 1:1 of ridge and furrow, (3) RFRHS with a sand mulched furrow, entire plastic mulch and the ratio 4:3 of ridge and furrow, (4) RFRHS with a sand mulched furrow, entire plastic mulch and the ratio 5:3 of ridge and furrow, (5) RFRHS with a sand and plastic mulched furrow, bare ridge and the ratio 4:3 of ridge and furrow, (6) RFRHS with an entire plastic mulch and the ratio 4:3 of ridge and furrow, (7) conventional ridge planting with a plastic mulched ridge, and (8) flat gravel–sand mulched field plus 23 mm supplementary irrigation. Soil temperature for RFRHS with a gravel–sand plus plastic mulched furrow was slightly lower than that of flat gravel–sand mulch. The RFRHS caused a sig- nificant increase in watermelon yield and WUE. The increase in watermelon yield and WUE was greatly influenced by the ratio of ridge and furrow when RFRHS was combined with gravel–sand mulch. Water- melon yield was highest for the 1:1 ratio, and WUE was highest for the 5:3 and 1:1 ratios of ridge:furrow, and these were significantly greater than that of flat gravel–sand mulch, without or with irrigation. The use of ridge with plastic film mulch increased the beneficial effect of RFRHS on yield. The watermelon yield and WUE for non-plastic-mulched ridge were even lower than that of flat gravel–sand mulch. In summary, the findings suggest that RFRHS with gravel–sand mulched furrow plus plastic film mulch, and 1:1 ratio of ridge:furrow, would facilitate the use of limited rainfall most efficiently in improving watermelon yield, by reducing ET and increasing WUE in this semiarid region.