不同施氮时期对红壤旱地花生生物量和氮素累积的影响

摘要

以花生品种粤油256为供试材料,采用田间随机区组试验,设置6个处理:不施氮肥(CK)、氮肥全部基施(N10∶0∶0,当地习惯施氮方式)、氮肥70％基施+30％花针期施用(N7∶3∶0)、氮肥50％基施+50％花针期施用(N5∶5∶0)、氮肥50％基施+30％花针期施用+20％结荚期施用(N5∶3∶2)、氮肥30％基施+50％花针期施用+20％结荚期施用(N3∶5∶2),研究不同施氮时期对南方红壤旱地花生生物量累积、氮素累积、氮肥利用率和产量的影响.结果表明:所有处理的花生生物量累积、氮素累积均可用Logistic方程拟合,施氮时期显著影响花生生物量及氮素的累积特征,氮肥分次施用并适当后移可显著提高生物量及氮素的最大累积速率(vmax)、推迟吸收“峰值”的出现时间(tmax),延长生物量及氮素快速累积的持续时间(△t),从而有利于提高花生产量及氮肥利用率,但氮肥后移比例过大(N3∶5∶2)也不利于肥效的充分发挥.本试验条件下,以氮肥50％基施+30％花针期追施+20％结荚期追施(N5∶∶∶2)的效果最好,其产量达到4 918.5kg·hm-2,较CK增产20.0％,较当地传统的一次性施肥也可增产9.8％.合理调控施氮时期是提高我国南方红壤旱地花生产量和氮肥利用率的有效措施,本研究可为该区域花生的科学合理施肥、高产高效栽培提供理论依据.%To explore the effects of nitrogen (N) application time on plant biomass and N accumulation,N utilization efficiency,and peanut yield in upland red soil,a field randomized block experiment,with Yueyou 256 as the test material,was carried out in this study.There were 6 treatments,which were no N fertilizer (CK),100％ N basal application (N10∶ 0∶ 0,local traditional N application method),70％ N basal application and 30％ N topdressing at flowering stage (N7∶ 3∶0),50％ N basal application and 50％ N topdressing at flowering stage (N5∶ 5∶ 0),50％ N basal application and 30％ N topdressing at flowering stage and 20％ N topdressing at pod setting stage (N5∶ 3∶ 2),and 30％ N basal application and 50％ N topdressing at flowering stage and 20％ N topdressing at pod setting stage (N3∶ 5∶2).The results showed that plant biomass and N accumulation among all treatments could be described by logistic equation,and their accumulation characteristics were significantly affected by N application time.Split application and appropriate delay could significantly accelerate the maximal speed of biomass and N accumulation (vmax);the maximal speed (tmax) would be postponed and the duration of rapid accumulation (At) would be prolonged.Therefore,the N utilization efficiency and peanut yield significantly improved.But it was negative for N efficiency when a large proportion of N application was delayed (N3∶ 5∶2).In this study,the peanut yield reached maximum under N5∶ 3∶2 treatment (4 918.5kg · hm-2),which increased 20.0％ and 9.8％ compared to CK and local traditional N application method (N10∶ 0∶0),respectively.In conclusion,reasonable N application time was the effective way to increase peanut yield and N utilization efficiency.This study could provide theoretical support for scientific and rational fertilization and high yield and high efficiency cultivation of peanut in upland red soil in South China.