Abstract:

To investigate the effects of climate warming and combined application of organic and inorganic fertilizer on soybean growth and yield,field experiments were conducted using infrared radiation warming systems to simulate temperature elevation.The experimental design included two temperature levels(T0:Ambient temperature;T1:Warming by 2.9 ℃)and two fertilization regimes(SF:Sole inorganic fertilizer;OF:Combined organic-inorganic fertilizer),aiming to examine the impacts of warming and fertilization practices on soybean dry matter accumulation,photosynthetic rate,leaf enzyme activities,and yield.Results demonstrated that compared to ambient temperature,warming shortened the pre-flowering and post-flowering growth periods by 3—4 d,5—6 d,respectively.Warming significantly reduced leaf nitrate reductase(NR)and glutamine synthetase(GS)activities during the pod-filling stage,decreased leaf area index(LAI)by 9.0%—13.7%,and suppressed net photosynthetic rate,collectively leading to 4.1%—19.3% reductions in post-flowering plant height and aboveground dry matter accumulation.In contrast,the combined organic-inorganic fertilization enhanced NR and GS activities,improved post-flowering photosynthetic efficiency,promoted plant growth,and increased the aboveground dry matter accumulation by 4.1%—15.3% compared to sole inorganic fertilization,with a significant interaction observed between NR and alanine aminotransferase activities.Yield analysis revealed that warming caused 9.7%—16.6%,13.3%—19.0% declines in pods per plant and grains per plant,respectively,resulting in 13.7%—21.1% yield reductions.Conversely,organic-inorganic fertilization increased grains per plant by 12.5% and pods per plant by 9.9%—10.5%,achieving 7.6%—10.8% yield improvements.Notably,significant positive correlations were detected among LAI,photosynthetic rate,nitrogen metabolism enzyme activities,and final yield.These findings demonstrate that climate warming inhibits post-flowering photosynthetic efficiency and aboveground growth in soybeans,while integrated organic-inorganic fertilization partially mitigates warming-induced yield losses through enhancing enzyme activities and photosynthetic performance,providing critical insights for adaptive agricultural practices under global warming scenarios.

Key words: Soybean, Warming, Combined application of organic and inorganic fertilizer, Photosynthetic characteristics, Yield

CLC Number: 

• S565.1