新疆‘叶尔羌’扁桃果实不同生育期叶片氮磷钾光谱特性研究

Leaf spectral characteristics of ‘Yarkent'almond and its sensitivity to N,P,K at different growth periods in Xinjiang

【目的】通过分析果实不同生育期叶片光谱反射率对N、P、K的响应,探寻采用叶片光谱指数诊断N、P、K敏感时期,为新疆莎车‘叶尔羌’扁桃简便快捷的非破坏性营养诊断提供最佳时间窗。【方法】采用"3414"肥料效应试验,利用Unispec-SC光谱仪测定莎车‘叶尔羌’扁桃在不同N、P、K施肥水平下果实座果期、膨大期、硬核期、成熟期叶片的光谱反射率。【结果】‘叶尔羌’扁桃果实不同生育期叶片光谱反射率波动取决于波长,在可见光波段变异最小。光谱反射率总体上呈现硬核期>座果期>膨大期>成熟期。在不同N、P、K施肥水平下,‘叶尔羌’扁桃果实不同生育期光谱指数(ND705)之间均存在显著差异(P<0.05)或者极显著差异(P<0.01)。叶尔羌扁桃果实座果期、膨大期、硬核期、成熟期叶片氮素的敏感波段分别为815 894 nm,375 398 nm,608 616 nm,429 437 nm;磷素的敏感波段为766 802 nm,1023 1063 nm,708 713 nm,1130 nm;座果期、膨大期、成熟期叶片钾素的敏感波段分别为815 894 nm,345 368 nm,475 491 nm。【结论】果实成熟期与硬核期是N、P、K叶片光谱营养诊断的敏感时期。叶尔羌扁桃果实座果期、膨大期、硬核期、成熟期叶片N素的敏感波段分别为815 894 nm,375 398 nm,608 616 nm,429 437 nm;P素的敏感波段为766 802 nm,1023 1063 nm,708713 nm,1130 nm;座果期、膨大期、成熟期叶片钾素的敏感波段分别为815 894 nm,345 368 nm,475 491 nm。

【Objectives】The sensitive period of leaf spectral index was studied by analyzing the leaf spectral reflectance in the response to nitrogen（ N）,phosphorus（ P） and potassium（ K） fertilizer at different growing stages of ‘Yarkent＇almond in Shache of Xinjiang aiming to provide a non-invasive,simple and rapid nutrition diagnosis of N,P,K. 【Methods】Using ＂3414＂fertilizer experiment and ‘Yarkent＇almond as tested material,the leaf spectral reflectance was measured using Unispec-SC spectrometer at fruiting,expanding,stone hardening and maturing stages of almond tree under different N,P,K fertilizer levels. 【Results】The fluctuation of leaf spectral reflectance of ‘Yarkent＇almond depended on the wavelengths at all the growing stages,and the least variation was in the range of visible wavelength. The leaf spectral reflectance was generally in the order of stone hardening stage fruiting stage expanding stage maturing stage. The leaf spectrum indexes（ ND705） of‘Yarkent＇almond was significantly（ P 0. 05） and extremely significantly（ P 0. 01） different among different N,P,K fertilizer levels at all growing stages. The spectral sensitive band of foliar N concentration was 815-894 nm,375-398 nm,608- 616 nm and 429- 437 nm at fruiting stage,expanding stage,stone hardening stage and maturing stage,respectively. The spectral sensitive band of foliar P concentration was 766-802 nm,1023-1063 nm,708-713 nm and 1130 nm at above 4 stages. For foliar K concentration,the spectral sensitive band was 815-894 nm,345-368 nm and 475- 491 nm at fruiting stage,expanding stage and maturing stage,respectively. 【Conclusions 】 The sensitive periods for leaf spectral nutrition diagnosis of N,P and K in ‘Yarkent＇almond are at mature stage and stone hardening stage. The spectral sensitive bands for N are 815-894 nm,375-398 nm,608-616 nm and 429-437 nm at fruiting stage,expanding stage,stone hardening stage and maturing stage,respectively; those for P are766-802 nm,1023-1063 nm,708-713 nm and 1130 nm; and those for K are 815-894 nm,345-368 nm and475-491 nm at fruiting stage,expanding stage and maturing stage,respectively.