灌水频率对绿洲菊芋耗水特征及水分利用效率的影响

Effect of Irrigation Frequency on Water Consumption and Water Use Efficiency of Jerusalem Artichoke( Helianthus tuberosus. L) in Oasis Region

灌水频率对作物耗水特征和水分利用效率有重要影响,但对以收获地下块茎为主要目的的经济作物研究并不多见。以菊芋为材料,分别在苗期(S)、枝繁叶茂期(L)、现蕾期(B)和开花期(F)施加不同灌水组合,包括苗期600 m3/hm2(S600,下同)处理J1、S600+L600为J2、S600+B600为J3、S600+L300+B900为J4、S600+L900+B300为J5、S600+L600+B300+F900为J6及全生育期不灌水的对照CK,研究菊芋农田水分利用状况。结果表明,枝繁叶茂期和苗期是菊芋水分消耗和需求最大的时期,其次为现蕾期。不同灌水频率下菊芋苗期耗水量、耗水强度及耗水模数差异不大(p>0.05),但与不灌水相比差异显著(p<0.05)。枝繁叶茂期和现蕾期缺水导致菊芋耗水量和耗水强度显著下降,而开花期灌水菊芋耗水量、耗水强度及耗水模数显著增大。菊芋全生育期耗水量随灌水频率和灌水量增大而增大,但灌水频率和总灌水量一定时,不同生育期灌水量分配对菊芋耗水量无显著影响。不同灌水频率下菊芋全生育期耗水量比不灌水显著增加55.3%~205.6%,灌水频率越高耗水量越大。菊芋水分利用效率随灌水频率和灌水量增大而降低,但相同灌水频率和灌水量下菊芋生育期内灌水量不同时水分利用效率差异不大。总体而言,以收获地下块茎为主要目的的经济作物在耗水规律和水分利用特征方面明显不同于以收获籽粒为目的的粮食作物,应保证营养生长期和并进生长阶段的水分供应以满足蒸腾需水和光合同化对水分的需求,而生殖生长期则应适当减少灌水量以抑制作物奢侈蒸腾,提高水分利用效率。

Irrigation frequency has important effect on crop water consumption and water use efficiency（ WUE）,but there is seldom research on irrigation in underground tuber-harvested economic crops. Jerusalem artichoke water consumption and WUE were determined in compounded irrigation treatments with the irrigation time in the stages of seedling（ S）,lush foliage（ L）,budding（ B）,and flowering（ L）,respectively. The treatments were respectively designed as J1,in which crops were watered 600 m^3/ hm^2（ S600. The same below.）,J2（ S600 ＋L600）,J3（ S600 ＋ B600）,J4（ S600 ＋ L300 ＋ B900）,J5（ S600 ＋ L900 ＋ B300）,J6（ S600 ＋ L600 ＋ B300 ＋ F900）,and CK,in which crops were never watered. The result indicated that water was consumed and required the most at lush foliage and seedling stage of jerusalem artichoke,followed by budding stage. The difference was not significant（ p 0. 05） in the periodic water consumption（ PWC）,daily water consumption（ DWC）,and the ratio of periodic water consumption in total water use（ RPWC） at jerusalem artichoke seedling stage under different irrigation frequency,but significant difference was found between the irrigated plants and that never watered. PWC and DWC were significantly decreased by water stress at lush foliage and budding stage,while PWC,DWC,and RPWC significantly increased by watering at flowering stage. The total water consumption（ TWC） of jerusalem artichoke increased with the increase of irrigation frequency and water application,however,different irrigation distribution during plant growth stages had no significant effect on TWC under the same irrigation frequency and water application. TWC was significantly increased by 55. 3% ~ 205. 6% in irrigated plots than never watered ones,and the higher irrigation frequency,the more water consumption. The WUE reduced with the increase of irrigation frequency and water application,but no difference was found in WUE of jerusalem artichoke subjected to different irrigation distribution during crop growth stages under the same irrigation frequency and water application. Therefore,there was obvious difference in water consumption and water use efficiency between underground tuber-harvested economic crops and grain-harvested plants. Fully water application during nutrition growth period and early productive period should be provided to meet water requirement in evaporation and assimilation while less water should be applied during reproductive stage.