不同水分处理对冬小麦产量和水分利用效率的影响

为探明甘肃河西走廊地区不同水分处理对冬小麦产量和水分利用效率的影响,以冬小麦临抗2号为试验材料,在冬灌水(180mm)相同的条件下,其他生育期以灌水量和灌水次数不等共设置5个处理。结果表明,返青期各层土壤有效含水量(AWC)均较低(2.37mm),至拔节期突增(9.88mm),随着生育期的推进,逐渐降低,成熟期降至2.54mm,特别是处理W1和W2在成熟期0～60cm层处于萎蔫点以下。处理间AWC的差异在灌浆期表现最为明显,尤其处理W1和W3,在0～60cm层AWC呈显著(P<0.05)和极显著(P<0.01)差异。冬小麦日耗水强度最大的时期是抽穗～开花期,阶段耗水量最大的时期是播种～返青,冬灌水充足是保证出苗率和后期冬小麦的正常生长基本条件。处理W3具有最高籽粒产量(6296.52kg/hm²)、千粒重(53.12g)和单位面积穗数(61.83万穗/hm²),但相对灌水较少的处理W4(籽粒产量6240.37kg/hm²)而言,其水分利用效率(WUE)和灌溉水利用效率(IWUE)均较低。相关分析表明,产量与千粒重(R=0.99^**)、WUE(R=0.97^**)、开花期～成熟期耗水量(CA_m)(R=0.88^*)、全生育期耗水量(CA_t)(R=0.88^*)呈极显著(P<0.01)正相关,表明生育后期水分胁迫,加速了冬小麦的衰老进程,灌浆期缩短,千粒重下降,最终表现为产量下降。综合考虑各种因素,处理W4具有重要的推广价值。

Effects of irrigation on grain yield and water use efficiency of winter wheat

The effects of irrigation on grain yield and water use efficiency of the winter wheat, Lingkang-2 were investigated. Five experimental treatments were designed on the basis of different irrigation amounts during the whole growing period. The soil available water content (AWC) changed with different growth stages, with a smaller value (2.37 mm) at the raising stage and larger one (9.88 mm) at the jointing stage, and with the maturity stage (2.54 mm) in between. The latter stage even had negative values in the 0-60 cm soil layers at maturity for W1 and W2. The milking stage was significantly different for all treatments. The maximum daily consumption of water was at heading-flowering and sowing-reviving, which showed that pre-winter irrigation contributes to improved emergence rates and promotes growth of winter wheat. W3 had the highest grain yield (6 296.52 kg/ha), grain weight (53.12 g) and ears per unit area (61.83 Spike×10⁴/ha) while water use efficiency (WUE) and irrigation water use efficiency (IWUE) were lower. However, compared with W3, W4 had the higher WUE and IWUE, and its grain yield was a little lower, at 6 240.37 kg/ha. Correlation analysis showed that there were highly significant positive correlations between yield and grain weight (R=0.99^**), WUE (R=0.97^**), at flowering-maturity (CA_m) (R=0.88^*), and total growth (CA_t) (R=0.88^*), indicating that water stress at the late growth stage accelerated the aging process of winter wheat, shortened the grain filling period, reduced grain weight, and eventually led to decline of grain yield. Considering the impact of different irrigation treatments on grain yield and water use efficiency of winter wheat, the W4 treatment was the most important.