不同氮肥水平下叶面喷施烯效唑对套作大豆生长和氮代谢的影响

以大豆品种‘贡选1号’为试验材料,在玉米-大豆套作模式下,研究在不同氮肥水平下叶面喷施烯效唑对大豆植株生长和根系氮代谢的影响。结果表明:烯效唑在不同施氮水平下均具有显著的控旺效果,使株高、第1节间长以及株高/茎粗比值降低,茎粗、分枝数以及地上部干物质量增加;烯效唑促进植株氮代谢,使植株地上部、地下部全氮含量以及根系伤流量增多,伤流中NO3--N、NH4+-N含量、氨基酸总量以及天冬氨酸、苏氨酸等氨基酸含量上升,NH4+-N/NO3--N比值、谷氨酸、甘氨酸等氨基酸含量降低;在低氮肥水平(0kg.hm-2)下以喷施60mg.kg-1烯效唑,中氮肥水平(32.4kg.hm-2)下喷施30mg.kg-1烯效唑,高氮肥水平(64.8kg.hm-2)下喷施60、90mg.kg-1烯效唑效果较优,能有效控制植株地上部旺长和促进根系对氮素的吸收、同化能力、代谢能力,提高植株氮循环水平。

Effects of foliar spraying uniconazole on growth and nitrogen metabolism of relay strip intercropping soybean under different nitrogen levels

Effect of foliar spraying uniconazole on growth and nitrogen metabolism of soybean Glycine max(L.) Merr.] cultivar ’Gongxuan 1’ at different nitrogen levels was studied under maize-soybean relay strip intercropping system.The results showed that, uniconazole had strong morphological effects to control excessive vegetative growth of soybean under different nitrogen levels,which could decrease plant height,the first internode length,the ratio of plant height and stem diameter,increase stem diameter,branch number and dry matter mass of shoot;uniconazole had significant physiological effects to promote nitrogen metabolism of soybean plants,which could increase nitrogen content of shoot and root,the amount of bleeding sap,NO3——N content and NH4+-N content in bleeding sap,the total amino acid content and the contents of amino acids such as Asp and Thr,decrease the ratio of NH4+-N and NO3——N,the contents of amino acids such as Glu and Gly.All results showed that the excessive vegetative growth of shoot was suppressed and the uptake of nitrogen,assimilation,amino acid synthesis and transportation were promoted by foliar sparing uniconazole with a moderate concentration of 60 mg·kg-1 under low nitrogen level(0 kg·hm-2),or a low concentration of 30 mg·kg-1 under moderate nitrogen level(32.4 kg·hm-2),or the higher concentrations of 60 or 90 mg·kg-1 under higher nitrogen level(64.8 kg·hm-2).