摘要
光合性能是决定作物产量形成的关键,氮肥的合理施用是调控作物光合特性和产量形成的重要措施.于2016—2017年开展盆栽试验,研究了减氮和施肥方式对甘薯叶片光合作用和叶绿素荧光特性的影响.试验以常规习惯基施氮肥100 kg·hm^(-2)为对照(FP),在常规施氮量的基础上减氮20%,同时设置3种氮肥运筹方式:100%基施(JS)、100%移栽后35 d追施(KS)、50%基施+50%移栽后35 d追施(FS).结果表明:与常规基施氮肥100 kg·hm^(-2)相比,减氮条件下氮肥全部基施显著降低了全生育期甘薯光合性能,但追施处理显著提高了块根膨大期净光合速率(P_n)、气孔导度(g_s)、胞间CO_2浓度(C_i)和叶绿素(Chl a+b)含量.不同处理下,P_n、g_s、C_i和Chl a+b均以50%基施+50%追施处理最高.减氮分施处理甘薯块根膨大期的PSⅡ实际光化学效率(Φ_(PSⅡ))、光化学淬灭系数(q_P)、PSⅡ最大光化学效率(F_v/F_m)和PSⅡ潜在活性(F_v/F_o)提高,而初始荧光(F_o)和非光化学淬灭系数(NPQ)则降低.氮肥分施通过提高PSⅡ的光化学效率和电子传递速率,降低光能的热耗散,提高了甘薯块根膨大期功能叶的光合速率.2个品种不同年际间表现相同.表明氮肥一次性基施或追施均不利于提高甘薯叶片光合性能.减氮20%水平下,50%基施+50%追施可减缓叶片早衰,延长叶片功能期,提高甘薯的光合生产能力和生物量,有利于产量形成.
Crop productivity depends on photosynthetic source capacity.Appropriate nitrogen(N)fertilizer management is beneficial for improving growth,photosynthetic capacity and thereby increasing crops yield.A two-year pot experiment was conducted with four N treatments,i.e.,conventional basal application 100 kg N·hm-2 as control(FP),a total of 80 kg N·hm-2 applied either 100%at basal application(JS),100%at tuber initiation stage(35 d after transplant,KS),50%at basal application and 50%at tuber initiation stage(35 d after transplant,FS),to examine the effects of reduced nitrogen fertilizer combined with application methods on the photosynthesis and chlorophyll fluorescence characteristics of sweetpotato(Ipomoea batatas)during summer 2016 and 2017.The results showed that the conventional basal application of a reduced N rate decreased photosynthesis of sweetpotato during the final growth phases compared to conventional application,dressing application relatively delayed late-season leaf senescence as indicated by the increased net photosynthetic rate(Pn),stomatal conductance(gs),intercellular CO2 concentration(Ci)and chlorophyll(Chl a+b)content during tuber expansion period.Split application of N fertilizer had noticeably higher Pn,gs,Ci and Chl a+b than other treatments.Furthermore,split application of N fertilizer had a significantly higher photochemical efficiency of photosystemⅡ(Fv/Fm),quantum yield of electron transport(ΦPSⅡ),and photochemical quenching co-efficient(qP),but lower initial fluorescence(Fo)and non-photochemical quenching coefficient(NPQ)during tuber expansion period.The improved photosynthesis by split N was due to both increased Fv/Fm with higher electron transfer rate and reduced thermal dissipation of light energy in the tuber expansion period.Results were consistent between two sweetpotato cultivars across years.The results indicated that one-time fertilization at basal or tuber initiation stage were not conducive to sweetpotato leaf photosynthesis.The split N application was more beneficial in terms of delaying late-season leaf senescence,extending leaf function period,enhancing photosynthesis and biomass production under reduced N application rate,which would be beneficial for sweetpotato yield.
作者
杜祥备
王家宝
刘小平
夏家平
韩杨
DU Xiang-bei;WANG Jia-bao;LIU Xiao-ping;XIA Jia-ping;HAN Yang(Crop Research Institute,Anhui Academy of Agricultural Sciences,Hefei 230031,China;Soil Fertilizer Institute,Anhui Academy of Agricultural Sciences,Hefei 230031,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2019年第4期1253-1260,共8页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(31601266)
现代农业产业技术体系建设项目(CARS-10-C5)资助~~
关键词
甘薯
减氮运筹
光合特性
叶绿素荧光参数
sweetpotato(Ipomoea batatas)
nitrogen application management under reduced rate
photosynthetic characteristics
chlorophyll fluorescence parameter
