Global climate warming is characterized by diurnal and seasonal asymmetry,with greater increases at nighttime and in winter and spring.Growing evidence has recognized that night-warming in winter and spring significan...Global climate warming is characterized by diurnal and seasonal asymmetry,with greater increases at nighttime and in winter and spring.Growing evidence has recognized that night-warming in winter and spring significantly impacts winter wheat production.Pre-crop straw returning is the principal method for straw utilization,but the interactions between straw returning and night-warming on wheat yield and N use efficiency(NUE)remain unclear.Here,a consecutive three-year field experiment with two straw treatments(S0,straw removal;S1,straw returning)and two warming treatments(W0,no warming control;W1,night-warming)found that both S1 and W1 improved wheat grain yield and NUE,with W1 exhibiting more pronounced improvements.Notably,the interaction between S1 and W1(S1W1)further enhanced yield and NUE by 13.0 and 16.5%,respectively,compared to S0W0 through increasing grain number and 1,000-grain weight(threeyear average).Additionally,root growth and topsoil inorganic N content decreased in S1 before jointing,thereby reducing plant dry matter and N accumulation.However,W1 exhibited an opposite trend,thereby mitigating these negative effects.Simultaneously,under S1W1,increased N translocation to grain and post-anthesis dry matter accumulation,driven by greater N distribution to leaves and higher N metabolism enzyme activity,enhanced both yield and NUE.This improvement was supported by better root morphology and biomass,particularly in the 0-40 cm soil layer,boosting plant N absorption.Additionally,elevated soil N-acquiring enzyme activity after jointing increased the net N mineralization rate and microbial biomass N,enhancing soil N-supply capacity.As a result,post-jointing inorganic N content rose in the 0-20 cm layer while decreasing at 20-60 cm,thus reducing the apparent N surplus.Collectively,straw returning,night-warming,and their interactions enhanced root distribution and N-supply capacity after jointing in the topsoil layer,thereby increasing plant N uptake and its translocation to grains,along with post-anthesis dry matter accumulation,ultimately improving grain yield and NUE.展开更多
基金financially supported by the National Natural Science Foundation of China(32272215)the Collaborative Innovation Center for Modern Crop Production by Province and Ministry(CIC-MCP),Nanjing Agricultural University,China。
文摘Global climate warming is characterized by diurnal and seasonal asymmetry,with greater increases at nighttime and in winter and spring.Growing evidence has recognized that night-warming in winter and spring significantly impacts winter wheat production.Pre-crop straw returning is the principal method for straw utilization,but the interactions between straw returning and night-warming on wheat yield and N use efficiency(NUE)remain unclear.Here,a consecutive three-year field experiment with two straw treatments(S0,straw removal;S1,straw returning)and two warming treatments(W0,no warming control;W1,night-warming)found that both S1 and W1 improved wheat grain yield and NUE,with W1 exhibiting more pronounced improvements.Notably,the interaction between S1 and W1(S1W1)further enhanced yield and NUE by 13.0 and 16.5%,respectively,compared to S0W0 through increasing grain number and 1,000-grain weight(threeyear average).Additionally,root growth and topsoil inorganic N content decreased in S1 before jointing,thereby reducing plant dry matter and N accumulation.However,W1 exhibited an opposite trend,thereby mitigating these negative effects.Simultaneously,under S1W1,increased N translocation to grain and post-anthesis dry matter accumulation,driven by greater N distribution to leaves and higher N metabolism enzyme activity,enhanced both yield and NUE.This improvement was supported by better root morphology and biomass,particularly in the 0-40 cm soil layer,boosting plant N absorption.Additionally,elevated soil N-acquiring enzyme activity after jointing increased the net N mineralization rate and microbial biomass N,enhancing soil N-supply capacity.As a result,post-jointing inorganic N content rose in the 0-20 cm layer while decreasing at 20-60 cm,thus reducing the apparent N surplus.Collectively,straw returning,night-warming,and their interactions enhanced root distribution and N-supply capacity after jointing in the topsoil layer,thereby increasing plant N uptake and its translocation to grains,along with post-anthesis dry matter accumulation,ultimately improving grain yield and NUE.
