不同灌溉方式对冬小麦光合速率及产量的影响

Effects of different irrigation methods on photosynthetic rate and yield of winter wheat

研究微喷灌和漫灌不同灌水条件下冬小麦光合速率和产量的变化规律,试图探明华北冬小麦光合速率和产量对不同灌水处理的响应,为冬小麦合理浇水管理、提高产量和水分利用效率(WUE)提供依据。设置微喷灌和漫灌两种灌溉方式,微喷和漫灌分别设置4个灌水量和灌水时期组合处理,微喷处理灌水量分别为90、120、150 mm和180 mm,漫灌处理灌水量分别为83、130、201 mm和205 mm,对冬小麦产量、光合速率、蒸腾速率、LAI等进行了分析。试验结果表明,在灌水量相近条件下小麦生育期灌水量≤120 mm时,微喷方式较漫灌方式能显著提高小麦子粒产量和WUE,产量增加的主要原因是千粒重增大;灌水量≥180 mm时,微喷方式产量和WUE均低于漫灌方式。不同时期小麦叶片光合速率微喷处理均高于漫灌处理,蒸腾速率除拔节期微喷灌水量120 mm、灌溉4次处理(SI2)外,微喷处理亦均高于漫灌处理;微喷、漫灌两种方式小麦叶片光合速率和蒸腾速率的变化趋势基本相同,均是先增大后减小。微喷和漫灌方式均表现为随灌水量的增加小麦LAI逐渐增大,主茎绿叶片数逐渐减少;在灌水量相近条件下,微喷处理小麦LAI大于漫灌处理,而主茎绿叶片数小于漫灌处理。2012—2013年度冬小麦生育期灌水量较小情况下微喷方式增产增效显著,而灌水次数多、灌水量较大时,微喷方式由于小麦LAI过高,群体郁闭,通风透光差,反而不利于产量和WUE的提高。微喷方式最优灌水处理为SI2,漫灌方式最优灌水处理为灌水量205 mm、灌溉4次(FI4)。

In order to provide reasonable winter wheat water management,improve yield,and enhance WUE,we studied the change trends of winter wheat photosynthetic rate and yield under micro-sprinkler irrigation and furrow irrigation,and tried to explore the responses of those to different irrigation treatments in North China. The experiment was employed with two irrigation methods： micro-sprinkler irrigation（ 90,120,150 mm and 180 mm）and furrow irrigation（ 83,130,201 mm and 205 mm） that respectively included four irrigation amounts and stages. Grain yield,photosynthetic rate,transpiration rate and LAI of winter wheat were analyzed. The results showed that in the same irrigation amount condition,the irrigation amount during wheat growth period was equal to or less than 120 mm. Micro-sprinkler irrigation significantly increased grain yield and WUE of wheat,mainly due to the increase of 1 000 grain weight. When the amount of irrigation was equal to or more than 180 mm,yield from microsprinkler irrigation and WUE was lower than that with furrow irrigation. Photosynthetic rates of wheat leaves with micro-sprinkler irrigation at different stages were higher than those with furrow irrigation. The transpiration rates by micro-sprinkler irrigation treatments were higher than those by furrow irrigation treatments,excepted for micro-sprinkler irrigation with an amount of 120 mm and 4 times of irrigation treatment（ SI2） at jointing stage. Changing trends for photosynthetic and transpiration rates with micro-sprinkler irrigation and furrow irrigation were basically the same,both of which became increased first and then went decreased. Wheat LAI with micro-sprinkler irrigation and furrow irrigation were gradually increased with the escalation of irrigation amount,and the main stem leaf number became gradually reduced. In the same irrigation amount condition,wheat LAI by micro-sprinkler irrigation was greater than that by furrow irrigation,while green leaf numbers were fewer than those by furrow irrigation. In the2012—2013 annual rainfall conditions,grain yield and WUE with micro-sprinkler irrigation treatments were higher than those with furrow irrigation with less irrigation amount,while high LAI and population density,and poor ventilation decreased grain yield and WUE under the condition with additional irrigation times and increased irrigation amount. SI2 was the optimal irrigation treatment for micro-sprinkler irrigation. For furrow irrigation,the parameter with an irrigation amount of 205 mm and 4 times（ FI4） was optimal.