In oasis irrigation agricultural region, water resources deficit is one of the most serious constraints for crop production. However, the insufficient academic support for how compact planting affecting crop water consumption has led to a great short slab on increasing yield and water use efficiency (WUE) simultaneously through the regulation of plant density in practices. Under the same fertilization and irrigation level, a field experiment was carried out in 2012-2015 in order to investigate the water consumption characteristics, yield and water use efficiency of maize under different density levels (D1, 75 000 plants ha-1, low; D2, 87 000 plants ha-1, medium; and D3, 99 000 plants ha-1, high). Withincreasing planting density the total water consumption (ET) increased in whole growth stage, but had no significant changes from sowing to jointing stage and from filling to full ripe stage. The total ET in high and medium density treatments significantly increased by 22.8% and 14.4% on average of four years, while by 28.4% and 18.2% on average of four years mainly in big trumpet to silking stage, respectively, compared with low density treatment. Similarly, increasing planting density could reduce invalid water consumption and increase water use efficiency, the high and medium density treatments reduced evaporation (E) in whole growth stage, by 56.5 mm and 27.6 mm, significantly decreased average daily evaporation from jointing to filling, and even greatly from big trumpet to silking stage, with the decreased values of 0.51 mm and 0.27 mm, respectively, compared with low density treatment. For E/ET, it was decreased with planting density increases, and the E/ET under high and medium density was reduced by 34.5% and 18.8%, respectively, especially from jointing to big trumpet, which decreased by 22.1% and 10.7%, respectively. On average, the grain yield under high and medium density was 17.9% and 14.8% greater than that under low density, but the difference was not significant. The water use efficiency (WUE) under high, medium and low density was 18.2, 19.3, and 16.8 kg ha-1 mm-1, respectively. While, the irrigation water use efficiency (IWUE) under high and medium density was increased by 34.5% and 19.6%, respectively, compared with low density. Therefore, further increasing planting density is favorable to improve grain yield and IWUE under the condition of traditional water supplement and film mulching in Oasis irrigation region.
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