补施氮肥对秸秆覆盖条件下旱作冬小麦光合特性及产量形成的影响  

Effects of nitrogen topdressing on photosynthesis and yield formation of winter wheat under straw mulching

作　　者：杨超 付鑫 刘文清 王俊 YANG Chao;FU Xin;LIU Wen-qing;WANG Jun(College of Urbanand Environmental Sciences,Northwest University,Key Laboratory of Surface System and Environmental Carrying Capacity,Shaanxi Province,Northwest University,Xi'an 710127,China)

机构地区：[1]西北大学城市与环境学院,陕西省地表系统与环境承载力重点实验室,西安710127

出　　处：《生态学杂志》2021年第4期1012-1020,共9页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(31270484和31570440)资助。

摘　　要：基于旱作冬小麦秸秆覆盖定位试验,采用微区施肥方式研究了作物生育后期补施氮肥对作物光合特性及产量形成的影响。覆盖定位试验包括全年无覆盖(CK)、生育期秸秆覆盖9000 kg·hm^(-2)(HSM)、生育期秸秆覆盖4500 kg·hm^(-2)(LSM)和休闲期秸秆覆盖9000 kg·hm^(-2)(FSM)4个处理;微区施肥在小麦孕穗期进行,包括施氮和不施氮2个水平。结果表明:在未补施氮肥情况下,与CK处理相比,HSM和LSM处理显著降低了土壤硝态氮和铵态氮含量,HSM、LSM和FSM处理均显著降低了花后冬小麦旗叶净光合速率、气孔导度、蒸腾速率和旗叶瞬时水分利用效率,同时HSM和LSM处理籽粒产量分别降低了28.43%和21.74%(P<0.05);与未补施氮肥处理相比,补施氮肥后HSM、LSM和FSM处理土壤硝态氮和铵态氮含量及冬小麦旗叶光合特性均有显著提高,且冬小麦千粒重、地上生物量、籽粒产量及收获指数在各处理间均无显著性差异。冬小麦生育后期补施氮肥有利于解决秸秆覆盖导致的氮亏缺问题,促进花后冬小麦旗叶光合作用,降低生育期秸秆覆盖的潜在减产风险。Based on a long-term straw mulching experiment with micro-plot fertilization in the dryland winter wheat monoculture system,we investigated the effects of nitrogen topdressing on photosynthesis and yield formation.There were four treatments,including no mulching as control(CK),straw mulching at rates of 9000(HSM)and 4500 kg·hm^(-2)(LSM)during growing season,and at a rate of 9000 kg·hm^(-2) during summer fallow(FSM).Topdressing was applied at the booting stage.Without topdressing,soil NO3-^(-)N and NH4+-N concentrations were lower under HSM and LSM than under CK.Leaf photosynthesis rate,stomatal conductance,transpiration rate,and water use efficiency were lower under HSM,LSM and FSM than that under CK.Wheat grain yield was lower by 28.43%and 21.74%under HSM and LSM than under CK(P<0.05),respectively.With topdressing,soil NO3-^(-)N and NH4+-N concentrations and photosynthetic characteristics of winter wheat flag leaves in HSM,LSM and FSM treatments were significantly higher than those without topdressing.There was no significant difference in wheat thousand-grain weight,aboveground biomass,grain yield,and harvest index among all the treatments.Our results indicate that nitrogen topdressing at late growing stage of winter wheat would be a reliable measure to solve soil nitrogen deficit caused by straw mulching,promote leaf photosynthesis after anthesis,and reduce the potential risk of yield reduction resulted from straw mulching.

关 键 词：补施氮肥 秸秆覆盖 冬小麦 光合特性 籽粒产量 

分 类 号：S512.11[农业科学—作物学]