Study On Mulched Drip Irrigation Under Water Deficit Regulation Of Potato’s Growth Characteristic And Yield In Oasis Irrigated Area

The experiment about mulched drip irrigation under water deficit regulation of potato has been carried out in Zhangye Yimin Irrigation Experimental station during April to October in 2013. According to different water deficit levels and different growth periods of potato, the experiment was designed five water deficit regulation treatments and a full irrigation controlled treatment: WD1 is a low water deficit treatment in tuber initiation stage(soil moisture content was maintaining at 55% — 65% of Field Capacity,FC, Field Capacity). WD2 is a low water deficit treatment in tuber bulking period(55% ~65% FC); WD3 is a low water deficit treatment in starch accumulation stage(55% ~ 65%FC); WD4 is tuber formation with moderate water deficit(45% — 55% FC); WD5:is processing tuber expansion period of moderate water deficit(45% — 55% FC); CK is a control treatment which sufficient irrigation supplied(65% — 75% FC).Through the field experiment, this paper studies the influence of water regulated deficit irrigation(WDR) on the Different soil depth water content changes in the whole stages and contact 、 dry matter weight of different potato organs, product yield, and water use efficiency(WUE).The experiment result shows,1:water deficit in different growth periods can lead to the decreasing of the quality of dry matter existing in potato stem and leave, but can be increasing in potato tuber in whole growth periods gradually. 2:The mild and moderate regulated deficit irrigation during the formative period of potato tuber both have less influence than the moderate regulated deficit irrigation during the expanding period on the yield of potato. The greater degree the deficit irrigation has, the more serious the decreasing of yield has.3:The water deficit of potato have a great affection on water consumption in different periods, the greater degree the deficit irrigation has, the more significant difference between water consumption and full irrigation plots(CK). The highest water use efficiency( WUE) was maintained in low WDR potato during tuber initiation,significantly improved by 24.05%, 19.39%, 8.31% than that in medium WDR plots during tuber bulking, low WDR plots during potato starch accumulation and CK respectively.4:Dry weight of potatoes at different stages in the whole stages leaf dry weight、stem dry weight and stem tuber in tuber formation sensitivity to moisture is low,there is no obvious difference between the groups. Tuber bulking phase differencebetween the groups and mild rdi processing weight of dry matter of different organs were higher than moderate regulated deficit irrigation(rdi) processing.Therefore, potato membrane under drip deficit irrigation can affect the quality of dry matter of different organs, beneficial to the improvement of the water use efficiency.And compared with the whole growth period sufficient water treatment CK, tuber formation mild deficit irrigation at yield under the condition of slightly lower(5.31%reduction) can significantly improve the water use efficiency(14.3%) and irrigation water use efficiency(18.5%), so the tuber formation mild regulated deficit irrigation is the hexi corridor oasis in arid and semi-arid potato best agricultural irrigation strategy.