摘要：
The agricultural water-saving measures in Northwest oasis irrigation areas are mainly mulching with traditional plastic film. This process is increasingly challenged by lack of water resources and increasing environment pollution from the white plas-tic film. Therefore, reducing the plastic film use and identifying innovative water-saving technologies need to be carried out ur-gently. The experiment was conducted to explore the effects of conventional plastic film mulching (CM), plastic film mulching with reduced tillage (RtM) and plastic film re-mulching for two years (RM) under different irrigation levels on water consumption characteristics and water use efficiency (WUE) in the Hexi corridor oasis zone in 2014-2016. Both RM and RtM relative to CM could significantly increase soil water storage before sowing, respectively increasing 41.7 mm and 31.6 mm (15.9% and 12.1%) on average in three years. From corn seeding to early jointing stages (the first 40 days of the plants' life cycle), under the same irrigation level, the water consumption of RM decreased, compared with that of RtM and CM, but the ground evaporation be-tween plants increased. Also, there was a significant increase for soil evaporation/water consumption (E/ET). On the contrary, from early stage of corn jointing to harvesting stage, RM decreased E/ET by 13.2%, compared with CM, showing that RM is beneficial to reduce the useless water consumption in the later stage of corn production. There was no significant difference on E/ET between RtM and CM. When the water level was the same, the water use efficiency was the best in RtM and no significant difference between RM and CM. Under the same film mulching mode, the WUE of the middle water level irrigated maize was the highest, and there was no significant difference in water consumption, evaporation and E/ET between RM and CM during the whole growth period, indicating that RM is just like CM having the advantage of water saving and increasing efficiency. The re-search indicate that the biennial mulching shares the same water use outcome with the traditional annual mulching in Hexi oasis irrigation area, which could be adopted in the trial areas to save water and reduce the application of plastic film.%西北绿洲灌区以传统覆膜方式为主的农业节水措施受水资源不足和白色地膜污染的挑战日益加剧,地膜减量节水技术研究亟待开展.2014—2016年,在河西绿洲灌区进行田间试验,重点探讨不同灌水水平下,一膜覆两年(RM)处理、少耕覆膜(RtM)和传统覆膜(CM)对玉米农田耗水特征和水分利用效率(WUE)的影响.结果表明,RM和RtM相对于CM均能显著提高玉米播前土壤贮水量,3年平均增加41.7 mm和31.6 mm(提高15.9%和12.1%).玉米播种到拔节初期(全生育期前40 d),灌水水平相同时,RM较RtM和CM降低了耗水量但增加了棵间蒸发量,且棵间蒸发量/耗水量(E/ET)显著增大,相反从玉米拔节初期到收获期,RM的E/ET较CM降低13.2%,即RM有利于减少玉米生育后期的无效耗水量,RtM与CM则无显著差异.灌水水平相同时,RtM水分利用效率最优,RM与CM之间无显著差异.相同覆膜方式下,中灌水水平玉米的WUE最高,RM与CM整个生育期内的耗水量、棵间蒸发量及E/ET均无显著差异,表明一膜覆两年具有传统覆膜方式节水增效的优点.因此,在河西绿洲溉区,一膜覆两年具有与每年翻耕覆新膜同等的水分利用效果,是试验区可推广的节水、地膜减量生产技术.
