增效助剂对夏玉米减氮稳产的效应研究

Effect of Synergistic Additives on Nitrogen Reduction and Stabilizing Yield of Summer Maize

为探究减氮配施增效助剂对四川旱地夏玉米产量及氮素利用的综合效应,设置增效助剂拌常规复合肥减氮20%与30%,增效助剂螯合肥减氮20%、30%与40%,增效助剂螯合肥减氮40%+有机肥3000 kg·hm^(-2)(合计减氮27%),并设置空白对照(CK0)、一次性施用常规复合肥(CK1,施氮量225 kg·hm^(-2))、常规复合肥作底肥+尿素作追肥(CK2,施氮量225 kg·hm^(-2),底追比6∶4)共计9个处理,分析不同施肥模式与减氮梯度对夏玉米产量形成与氮素利用的调控。结果表明,增效助剂处理显著提高了开花后10~30 d夏玉米的叶面积指数(LAI)与相对叶绿素含量(SPAD)。增效助剂螯合肥减氮20%与30%、增效助剂螯合肥+有机肥合计减氮27%处理花后氮素积累量较CK1和CK2显著增加9.1%~14.6%和10.7%~16.4%,成熟期干物质、氮素积累量较CK1和CK2均显著增加。此外,增效助剂处理后产量较CK1、CK2提升,其中增效助剂拌常规复合肥减氮20%、增效助剂螯合肥减氮20%和30%、增效助剂螯合肥+有机肥合计减氮27%增产效果较明显。同时,增效助剂拌常规复合肥、增效助剂螯合肥、增效助剂螯合肥+有机肥模式下各处理氮素利用效率、氮肥偏生产力较CK1和CK2均显著提升,经济效益分别显著提高7.6%~12.6%和8.7%~13.8%。减氮稳产增效的原因在于配施增效助剂后可使肥料养分固持缓释,促进夏玉米花后养分吸收并增加花后干物质积累量和氮素积累转运量,进而提高氮素利用率。采用增效助剂拌常规复合肥,可实现减氮20%且稳产;增效助剂螯合肥,可实现减氮20%~30%且稳产或增产;增效助剂螯合肥配合有机肥3000 kg·hm^(-2),可实现减氮27%且增产。本研究可为采用增效助剂途径实现夏玉米减氮稳产提供理论依据。

To investigate combined effect of nitrogen reduction combine with synergist on yield and nitrogen utilization of dryland summer maize in Sichuan,a total of 9 treatments were set to analyze the regulation of different fertilization patterns and nitrogen reduction gradients on the yield formation and nitrogen utilization of summer maize.The treatments were synergistic agent+common compound fertilizer with 20%or 30%nitrogen reduction;synergistic agent chelated urea formaldehyde fertilizer reducing nitrogen by 20%,30%,or 40%;synergistic agent chelated urea formaldehyde fertilizer reducing nitrogen by 40%and combined with organic fertilizer(3000 kg·hm^(-2)),totally reducing nitrogen by 27%;No fertilization(CK0);one-time application of common compound fertilizer(CK1,applied at a rate of 225 kg·hm^(-2));and common compound fertilizer as base fertilizer+urea as topdressing fertilizer(CK2,applied at a rate of 225 kg·hm^(-2),base/topdressing,6/4).The results demonstrated a significant increase in LAI and SPAD values of summer maize 10-30 days after flowering when treated with synergistic agent.Treatments of synergistic agent+common compound fertilizer with 20%or 30%nitrogen reduction and synergistic agent chelated urea formaldehyde fertilizer reducing nitrogen by 40%and combined with organic fertilizer(3000 kg·hm^(-2)),totally reducing nitrogen by 27%showed a significant increase in nitrogen assimilation amount by 9.1%to 14.6%and 10.7%to 16.4%compared to CK1 and CK2.Additionally,the amount of dry matter and nitrogen accumulation at maturity significantly increased when compared to CK1 and CK2.Furthermore,the yield after the synergistic agent treatment was found higher when compared to CK1 and CK2.Notably,the yield increasing effects of synergistic agent+common compound fertilizer with 20%nitrogen reduction,synergistic agent chelated urea formaldehyde fertilizer reducing nitrogen by 20%and 30%,and synergistic agent chelated urea formaldehyde fertilizer reducing nitrogen by 40%and combined with organic fertilizer(3000 kg·hm^(-2)),totally reducing nitrogen by 27%exhibited significant differences.The nitrogen use efficiency and nitrogen partial productivity of each treatment significantly improved when using synergistic agent mixed with conventional compound fertilizer,synergistic agent chelated fertilizer,and synergistic agent chelated fertilizer+organic fertilizer,compared to CK1 and CK2.Additionally,the economic benefits also increased significantly,by 7.6%to 12.6%and 8.7%to 13.8%,respectively.The reason for nitrogen reduction,stable yield,and efficiency increase is that the combination of synergistic agent can slow down the release of fertilizer nutrients,thereby promoting nutrient absorption of summer maize after flowering and increasing dry matter accumulation.This promotes nitrogen accumulation and transport,ultimately improving nitrogen use efficiency.The use of synergistic agent mixed with conventional compound fertilizers can reduce nitrogen levels by 20%and stabilize production.Similarly,the use of synergistic agent in chelated fertilizers can lead to a nitrogen reduction of 20%to 30%,while stabilizing or even increasing production.Additionally,when synergistic agent is combined with chelated fertilizers and organic fertilizers at a rate of 3000 kg·hm^(-2),a nitrogen reduction of 27%and an increase in yield can be achieved.This study provides a valuable theoretical basis for utilizing synergistic agent to achieve nitrogen reduction and stable yield in summer maize.