Submitted to: International Geoscience and Remote Sensing Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/20/2000
Publication Date: 10/12/2000
Citation: Interpretive Summary: The study indicates that fluorescence technology could aid in the determination of nitrogen (N) fertilization requirements for field corn by nondestructive remote sensing methods of the canopy leaves. The paper compares laboratory and field fluorescence measurements and discusses design concepts and preliminary field trails of an advanced mobile field-based Laser Induced Fluorescence Imaging System with the potential to monitor stress conditions in a wide variety of vegetative ecosystems. The system is capable of simultaneously acquiring images of four fluorescence emission bands from areas of plant canopies equaling one meter square without interference of ambient solar radiation.
Technical Abstract: Studies were conducted to define changes in fluorescence properties of leaves from field grown corn (Zea mays L.) as they relate to varying levels of nitrogen (N) fertilization. The research was directed towardly: 1) providing a remote nondestructive sensing technique to aid in the determination of optimal rates of N fertilization in corn crops and 2) defining parameters for further development of fluorescence instrumentation to be operated remotely at field canopy levels. Fluorescence imaging bands centered in the blue (450 nm), green (525 nm), red (680 nm), far-red (740 nm), and ratios of these bands were compared with the following plant parameters: rates of photosynthesis, N to Carbon (C) ratio, pigment concentrations, and grain yield. Both the fluorescence and physiological measures exhibited similar curvilinear responses to N fertilization level. Significant linear correlations were obtained between fluorescence bands and band rations to certain physiological measures of plant productivity. The red/blue, red/green, far-red/blue, far-red/green fluorescence ratios are well suited for remote observation and provided high correlations to grain yield, LAI, N to C ratio, and chlorophyll content. Design concepts and a preliminary field trial test were made of a mobile field-based Laser Induced Fluorescence Imaging System (LIFIS).