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1、中国农学通报2014,30(3):85-90ChineseAgriculturalScienceBulletin基于冠层反射光谱的夏玉米叶片氮积累量估测李国强,吴士文,郑国清,张学治,冯晓,张杰,胡峰(河南省农业科学院农业经济与信息研究所,郑州450008)摘要:为实现夏玉米冠层氮素状况的实时无损监测,于2009—2010年连续2个生长季,通过不同玉米品种和施氮水平下的田间试验,研究夏玉米叶片氮积累量与冠层反射光谱的相关关系,提出叶片氮积累量的敏感光谱参数,并建立叶片氮积累量的定量估算模型。结果表明,夏玉米叶片氮积累量随施氮水平的提高而增加;可见光波段的460~670nm和
2、近红外区的780~1100nm是监测玉米叶片氮积累量变化差异的敏感波段;归一化植被指数(NDVI)、优化的简单比值指数(MSR)、优化土壤调节植被指数(OSAVI)、修正土壤调整植被指数(MSAVI)和土壤调整植被指数(SAVI)与叶片氮积累量相关性较好。利用不同年际独立试验数据对监测模型进行检验,以OSAVI为自变量构建的叶片氮积累量监测模型效果最优,相关系数(r)为0.6745,均方根差(RMSE)为1.2368。利用本研究确立的玉米叶片氮积累量与冠层反射光谱的定量关系,可用来定量估测叶片氮积累量的变化状况。关键词:夏玉米;冠层反射光谱;叶片氮积累量;监测模型中图分类号
3、:S512文献标志码:A论文编号:2013-0800MonitoringLeafNitrogenAccumulationinSummerMaizewithCanopyReflectanceSpectraLiGuoqiang,WuShiwen,ZhengGuoqing,ZhangXuezhi,FengXiao,ZhangJie,HuFeng(AgriculturalEconomy&InformationResearchInstitute,HenanAcademyofAgriculturalSciences,Zhengzhou450008)Abstract:Torealizen
4、on-destructiveandquickassessmentofleafnitrogenstatusinsummermaize,twofieldexperimentswereconductedwithdifferentmaizecultivarsandnitrogenlevelsacrosstwogrowingseason,andtime-coursemeasurementsweretakenoncanopyspectralreflectanceandleafnitrogenaccumulationduringtheperiodofexperiment.Baseonth
5、ecanopyreflectanceandderivedvegetationindex,weanalyzedthequantitativerelationshipsbetweenleafnitrogenaccumulationandcanopyreflectanceindifferentmaizecultivarsundervariednitrogenrates,andputforwardthesensitiveparametersandmonitoringequationforleafnitrogenaccumulation.Theresultsshowedthat,le
6、afcanopynitrogenaccumulationinmaizeincreasedwithincreasingnitrogenrates.Wavelengthsat460-670nmand780-1100nmweresensitivetoleafnitrogenaccumulationfornitrogendiagnosis.Leafnitrogenaccumulationwashighlycorrelatedwithnormalizeddifferencevegetationindex(NDVI),modifiedsimpleratio(MSR),optimalso
7、il-adjustedvegetationindex(OSAVI),modifiedsoil-adjustedvegetationindex(MSAVI),soil-adjustedvegetationindex(SAVI),2respectively.ComparingtheRandstandarderrorofregressionmodel,thespectralindexofOSAVIwasthetestparameterforpredictingleafnitrogenaccumulation.Themon