【作者】 李佛琳；

【导师】 赵春江； 曹卫星；

【作者基本信息】 南京农业大学 ， 作物栽培学与耕作学， 2006， 博士

【摘要】 利用光谱无损技术进行作物生长状况的实时监测和快速诊断是遥感和信息农学的一个重要课题，具有重要的理论和实践意义。本研究将高光谱手段应用到烟草，在中国主产烟区河南郑州和云南保山进行了烤烟、香料烟两种类型的不同氮肥供应田间试验，使用ASD Fieldspec FR2500光谱仪从田间鲜烟叶单叶水平和冠层两个尺度获取光谱数据，并对成熟鲜烟叶进行了室内光谱测定。分析了烟草光谱与生物物理化学指标之间的关系，旨在筛选烟草光谱与其生化组分之间最佳预测方法，为利用定量遥感技术监测烟草叶片生化组分、遥感品质监测等提供理论依据，为烟叶品质快速无损监测的应用奠定基础。 首先系统分析了烟草的光谱特性及其影响因素。烟草具有典型的植物反射特征。烟草叶片光谱因施氮因素、烟草类型、测定时期、叶位、叶面、干鲜叶等因素而异。烤烟烟叶室外反射光谱在可见和近红外等波段范围内的变异系数为32.8～58.7％。叶片的反射率，白肋烟类型在可见光、近红外波段都大于香料烟和烤烟。烤烟叶片反射率表现为上部叶＞中部叶＞下部叶。烤烟同一叶片的8个部位反射率光谱有差异、烤烟烟叶正反面反射率不同、烘烤过的烟叶光谱反射率大于鲜烟叶。随施氮水平的增加，烤烟叶片及香料烟冠层反射光谱均表现为可见光区的反射率逐渐降低，而近红外波段的反射率逐渐升高的趋势。光谱信息包含了许多因素及其相互影响，这些结果为烟草光谱监测的进一步研究提供了理论基础。 系统分析了田间不离体条件下烟叶光谱与烟叶化学品质指标之间的相关关系，筛选出一些与烟叶氮、烟碱、总糖、钾含量的显著相关的光谱参量，建立了相应的光谱诊断模型。其中氮反射指数NRI与叶片氮含量在各个测定时期都稳定一致的达到显著相关，两者决定系数(R~2)达0.703。由于总糖、还原糖、烟碱、钾各个测定时期的变化较大，分时期建立了总糖，烟碱、钾的估算模型，但是没有适合的还原糖估算模型。田间不离体条件下光谱方法诊断氮、钾含量品质指标最好，其次是烟碱和总糖。总体上田间不离体光谱方法模型的决定系数中等，可以满足一定精度要求下的需要。 在明确香料烟叶面积指数、叶片产量、生化品质指标变化的基础上，通过大量光谱参量的相关分析，建立了香料烟生长指标和主要化学品质指标的冠层光谱预测模型。各个测定时期各种生长和化学品质指标与冠层反射率的相关性变化较大。采用选用的光谱参量及综合性群体指标，光谱与生物物理化学参量的相关关系得到加强。结构性指标和功能性指标各个阶段均有稳定一致性的显著相关的光谱指数，而成分性指更多还原

【Abstract】 The nondestructive hyperspectral technology to monitor and detect crop growth status has demonstrated wide applicability in the field of remote sensing and informative agronomy. In this study, hyperspectral technology was applied to tobacco. A series of field experiments with flued-cured variety (FCV) tobacco and oriental tobacco types under nitrogen rates were conducted in Zhengzhou Henan and Baoshan Yunan, which belong to main tobacco production region in China. Leaf-scale and canopy-scale reflectance spectra were measured with ASD Fieldspec FR2500 over the growth stages at the field and laboratory. The objectives of this research were to determine the relationship between spectral characteristics and tobacco biophysical and biochemistry parameters, and to develop models for monitoring growth and quality traits based on spectral characteristics. Therefore, this work would provide theoretical basis for quantitative remote sensing and hyperspectral application on tobacco production. The results showed that:1. Spectral characteristics of tobacco were analyzed systemically corresponding to nitrogen rates, tobacco types, growth stages, leaf position at the stem, position within-leaf, adaxial and abaxial leaf surface, fresh and dry leaf. Tobacco has typical vegetation reflectance spectral characteristics. Range of reflectance variation coefficient of FCV tobacco leaf investigated was 32.8-58.7% at field in 350-2500nm. Leaf reflectance of burley tobacco was great than that of oriental tobacco and FCV tobacco in the visible and near-infrared regions. FCV tobacco leaf reflectance was, upper leaf >cutter leaf>lower leaf at the stem. The reflectance varied with positions within-leaf as well as adaxial and abaxial leaf surface in FCV tobacco. The reflectance of dry leaf was great than that of fresh leaf in FCV tobacco. Reflectance of FCV tobacco leaf and oriental tobacco canopy decreased at visible region and increased with nitrogen rates at near-infrared region. Reflectance of FCV tobacco leaf increased with growth progress at 400-1350nm region, of which reflectance varied greatly at visible region. While reflectance of oriental tobacco leaf decreased at visible regions and increased at near-infrared with growth progress. Spectra are the更多还原