智慧农业（中英文）SmartAgricultureVol.2,No.2
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129:718-726.detectorbasedonNIRS[J].PrecisionAgriculture,
[17]ANX,LIM,ZHENGL,etal.Aportablesoilnitrogen2014,15:3-16.
Near-FieldTelemetryDetectionofSoilNutrientBasedon
ModulatedNear-InfraredReflectanceSpectrum
JIAOLeizi,DONGDaming,ZHAOXiande,TIANHongwu
（NationalEngineeringResearchCenterofIntelligentEquipmentforAgriculture,Beijing100097,China）
Abstract:Propersoilnutrientscontentplaysanimportantroleinagriculturalproduction—undernutritionwouldreducecrop
yieldandqualityandovernutritionwouldcauseenvironmentalpollution.Thoughthetraditionalapproachesbasedonsampling
andchemicalanalysiscancomprehensivelyandaccuratelymeasuresoilnutrients,butthesoilsamplingandpretreatmentpro‐
cessarecumbersome,complicated,time-consuming,andcostly.Therefore,rapidandaccuratemeasurementofsoilnutrientsis
ofgreatsignificanceforprecisefertilizerapplication,whichcanincreaseyield,improvecropquality,andalleviateenvironmen‐
talpollution.Towardthisobjective,arapidsoilnutrientsdetectionmethodbasedonmodulatednearinfraredspectroscopyfor
activenear-fieldtelemetrywasproposed,whichcouldeffectivelyminimizeeffectofsunlightduringthemeasuringprocess.
Eightchannelsnarrow-bandlaserdiodeswithwavelengthsof1260,1310,1350,1410,1450,1510,1550and1610nmwerese‐
lectedasactivelightingsourcesformeasuringthereflectanceofsoilsamples.Eightchannelsnarrow-bandlaserdiodeswere
symmetricallyplacedonaconcentriccircle.Aphotodetectorwithacircularphotosensitiveareaof5mmindiameterwasplaced
atthecenteroftheconcentriccircletomaximizethereceptionoflaserbeamreflectedbysoil.Afocusinglenswasplacedin
frontofthephotodetectortocollectthelaserbeamreflectedfromthesoilsampletoincreasethesensitivity.Thesensingareaof
thephotodetectorwaslocatedatthefocusofthelens.seventyfourgroupsofsoilsampleswithknownNcontentweredivided
intotrainingset(54groups)andpredictionset(20groups)fordataanalysis.Thespectralreflectancesignificantlycorrelated
withsoilNcontentwasscreenedbyanalyzingthetrainingsetbasedonagenerallinearmodelandaquantitativemeasurement
2
modelwithRof0.97betweenthescreenedspectralreflectanceandsoilNcontentwasachieve.ThepredictedsoilNcontentob‐
2
tainedfrompredictionsetbasedontheestablishedmodelandthereferencedsoilNcontentofthepredictionsethadaRof0.9,
indicatingthatthismethodhasanabilitytoquickly,aswellasaccuratelydetectsoilnutrients.
Keywords:soilnutrients;nearinfraredspectrum;near-fieldtelemetry;lock-inamplifier;photoelecticdetection |
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