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为探明灌溉对干旱区冬小麦(Triticum aestivum)产量、水分利用效率(WUE)、干物质积累及分配等的影响,以甘肃河西走廊冬小麦适宜种植品种‘临抗2号’为材料进行了研究。在冬季灌水180 mm的条件下,生育期以灌水量和灌水次数等共设置5个处理,分别为:拔节期灌水量165 mm(W1)、拔节期灌水量120 mm+抽穗期灌水量105 mm(W2)、拔节期灌水量105 mm+抽穗期灌水量105 mm+灌浆期灌水量105 mm(W3)、拔节期灌水量75 mm+抽穗期灌水量75 mm+灌浆期灌水量75 mm(W4)、拔节期灌水量105 mm+抽穗期灌水量75 mm+灌浆期灌水量45 mm(W5)。结果表明:随着生育期的推进,土壤有效含水量(AWC)受灌水次数及灌水量影响更加明显;W3、W4处理的土壤各层AWC在灌浆期均较高;叶面积指数(LAI)下降慢,延缓了生育后期的衰老;生育后期干物质积累增加,提高了穗粒数、千粒重和籽粒产量。籽粒产量以W3处理最高,但W4具有最高的WUE,且籽粒产量与W3无显著差异,但W4较灌溉总量相同的W2和W5以及灌水量最少的W1具有明显的指标优势。W1、W2、W5处理灌浆期各层土壤AWC均较低,花后LAI下降快,干物质积累减少,灌浆持续期缩短,穗粒数和千粒重减少,最终表现为籽粒产量和WUE下降。灌浆期水分胁迫可促进花前储存碳库向籽粒的再转运,并随着干旱胁迫的加重而提高,对籽粒产量起补偿作用;水分胁迫提高了灌浆速率,但缩短了灌浆持续期。相关性分析表明,灌浆持续期、有效灌浆持续期、有效灌浆期粒重增加值和最大籽粒灌浆速率出现时间与千粒重和籽粒产量均呈正相关。综合考虑,拔节、抽穗及灌浆期各灌溉75mm是高产高WUE的最佳灌水方案。
To investigate the effect of irrigation on yield, water use efficiency (WUE), dry matter accumulation and distribution of winter wheat (Triticum aestivum) in arid area, the suitable winter wheat cultivar ’Linkang 2’ was studied in Hexi Corridor. Under the conditions of winter irrigation of 180 mm, five treatments were set up during the growth period, such as irrigation amount at jointing stage 165 mm (W1), irrigation at jointing stage 120 mm and irrigation at heading stage 105 mm W2), irrigation at jointing stage 105 mm + irrigation at heading stage 105 mm + irrigation at filling stage 105 mm (W3), irrigation at jointing stage 75 mm + irrigation at heading 75 mm + irrigation at filling stage 75 mm (W4) Amount of 105 mm + Heading irrigation 75 mm + filling irrigation 45 mm (W5). The results showed that the AWC was more affected by irrigation times and irrigation amount as the growth period progressed. AWC at the W3 and W4 treatments was higher at the grain filling stage and the LAI decreased Slow, postponed the post-growth senescence; increased dry matter accumulation during later growth, increased grain number per spike, 1000-grain weight and grain yield. The grain yield was highest in W3, but W4 had the highest WUE, and the grain yield was not significantly different from W3. However, W2 and W5 with the same amount of W4 as irrigation and W1 with the lowest irrigation had obvious index advantages. The AWC of W1, W2 and W5 treatments were lower in the soil layers at filling stage, the LAI decreased rapidly after anthesis, the dry matter accumulation decreased, the duration of grain filling decreased, the grains per spike and 1000-grain weight decreased, and finally the grain yield and WUE decreased. During the filling stage, water stress could promote the re-transport of pre-anthesis stored carbon pools to grain, and increased with the increase of drought stress, which compensated the grain yield. Water stress increased the filling rate, but shortened the duration of filling. Correlation analysis showed that duration of filling, duration of effective filling, effective grain filling increment and maximum grain filling rate appeared positively correlated with 1000-grain weight and grain yield. Taking into account, jointing, heading and filling irrigation of 75mm is the best high-yield WUE irrigation program.