微喷对冬小麦冠层微环境日变化及叶片水势的影响

Impact of Micro-sprinkler Irrigation on Diurnal Variation of Microenvironment of Canopy of Winter Wheat and Their Leaf Water Potential

采用裂区试验,以矮抗58为试验材料,在前期滴灌控水处理下,探究了不同的微喷处理对冬小麦冠层微环境、叶片水势和产量的影响。结果表明,在冬小麦灌浆后期微喷10 mm能显著降低冠层温度、二氧化碳摩尔分数,提高相对湿度、旗叶叶片水势。MW2处理(滴灌底墒水、拔节水和开花水,并在灌浆后期微喷10 mm)的产量、千粒质量最高,分别为6 952.39 kg/hm^2、45.44 g,均显著高于其他处理(P<0.05)。相关分析显示,产量与冠层温度呈极显著负相关、与旗叶叶片水势极显著正相关、与冠层相对湿度显著正相关。可见,滴灌底墒水、拔节水和开花水,并在灌浆后期微喷10 mm,能够改善冬小麦冠层微环境,缓解空气高温对小麦的胁迫,显著提高千粒质量,增加产量。

This paper investigated the impact of micro-sprinkler irrigation on diurnal change in microenvironment of winter wheat canopy, their leaf water potential and yield using split-plot experiment. We used the cultivar Ai- kang58 as the model plant. The results showed that irrigating 10 mm of water at late grain-filling stage could signif- icantly reduce the temperature and carbon dioxide concentration of the canopy, whereas increasing the relative hu- midity and leaf water potential of the canopy. The treatment of drip-irrigating at sowing, jointing and flowering stages, together with a further 10 mm of irrigation at late filling stage, gave the highest yield （6 952.39 kg/hm2） and 1000-grain weight （45.44 g）, which were significantly higher than those in other treatments. Analysis showed that the yield was negatively related to canopy temperature （P〈0.01）, while positively related to leaf water potential （P〈0.01） and relative humidity of the canopy （P〈0.05）. Therefore, drip irrigation at sowing, jointing and anthesis stages with further 10 mm of irrigation at late grain-filling stage could optimize the canopy microenvironment and alleviate thermal stress, significantly increasing yield and grain weight as a result.