氮肥基追比和调亏灌溉对小麦水分利用效率和产量的影响

Effects of Base-Topdressing Ratio of Nitrogen Fertilizer and Regulated Deficit Irrigation on Water Use Efficiency and Yield of Wheat

优化水肥管理对提高小麦生产效率,改善农业生态环境具有重要意义。在防雨棚下,采用桶栽土培法研究氮肥基追比和调亏灌溉对小麦水分利用效率、叶片光合速率的影响,为优化小麦水氮运筹模式提供依据。设置4种氮肥基追比(播前和拔节期施氮比例)处理,分别为10∶0、7∶3、5∶5和3∶7,记为N10∶0、N7∶3、N5∶5和N3∶7。2种水分处理:水分调亏(返青-拔节期)—复水—调亏(灌浆-成熟期),记为D;全生育期正常供水,记为N。结果表明,拔节期追施氮肥显著提高小麦灌浆期的单茎叶面积;相同水分条件下,N7∶3、N5∶5和N3∶7灌浆期单茎叶面积递增且显著高于N10∶0处理。水分调亏显著降低拔节期N10∶0处理小麦最上部展开叶的光合速率,对其他氮肥处理小麦光合速率的影响则未达显著水平;相同水分条件下,N5∶5处理拔节期和灌浆期均具有较高的光合速率。随追氮比例的增加,小麦叶片光合速率和水分利用效率呈先升后降的趋势。氮肥基追比和水分调亏显著影响小麦产量和水分利用效率,且两者对小麦产量存在显著的互作效应。综合考虑产量和水分利用效率等因素,水分调亏配合氮肥基追比处理比例为5∶5是最合理的水氮运筹模式。

Optimizing water and fertilizer management is of great significance for increasing wheat production efficiency and improving agricultural ecological environment.A barrel experiment was conducted under a fully automatic rain-proof shelter to investigate the effects of base-topdressing ratio of nitrogen fertilizer and regulated deficit irrigation on water use efficiency and photosynthetic rate of wheat,which provided a basis for optimizing wheat water and nitrogen operation model.Four nitrogen base fertilizer and top-dressing ration were subjected to 10∶0,7∶3,5∶5 and 3∶7,respectively,which were noted as N10∶0,N7∶3,N5∶5 and N3∶7;two levels of water treatment:both re-greeningjointing stage and grain-filling-maturity stage for water deficit regulation,noted as D;normal water supply during the whole growth period,noted as N.The results showed that append nitrogen fertilizer at jointing stage significantly increased the leaf area per stem at grain-filling stage.Under the same water condition,leaf area per stem among N7∶3,N5∶5 and N3∶7 treatments progressively increased and significantly higher than that in N10∶0 treatment.Regulated deficit irrigation significantly reduced the photosynthetic rate of wheat uppermost unfolding leaves in N10∶0 treatments at jointing stage;under the same water condition,N5∶5 treatment had a higher photosynthetic rate from jointing to grainfilling.In addition,with the increase of nitrogen-dressing ratio,the photosynthetic rate of flag leaf and water use efficiency increased first and then decreased.Both Nitrogen and water deficit regulation significantly affected wheat yield and water use efficiency,and there existed a significant interaction effect on wheat yield.Regulated deficit irrigation combined with N5∶5 nitrogen application treatment is the most reasonable combination based on the grain yield and the water use efficiency as well as other factors under the conditions of this experiment.