Portable system approach of monitoring plant nutrient deficiency using fiber optic spectrophotometry

摘要

Abstract: In this paper, a portable sensing system is developedusing fiber optic spectroscopy principle for measuringand detecting of stresses induced in plants due tonutrient deficiencies. Chlorophyll fluorescence inplants is used to monitor the effects of nutrientstress in plants. As this method aims at providing anearly detection and warning of nutrient deficiencies,it gives an alternative to argument currentsemi-quantitative and destructive methods of nutrientanalysis. Our early papers had demonstrated significantdifferences in the color reflectance of plants' leaveswhen plants were subjected to various nutrient-deficient media. Developed using off-the-shelfcomponents, this digital sensing optical system couldmeasure and detect the slight variation in the plants'reflectance and hence its chlorophyll levels. Theserelative levels of chlorophyll are determined bymeasuring the plants' color reflectance of light whileusing the wavelength of the healthy plants as areference for comparison. This system comprises of aminiature spectrometer containing 1024 CCD detectorscovering a visible light spectrum of wavelength rangingfrom approximately 400 nm to 800 nm and a reflectiveprobe. A laptop with a PCMCIA A/D data acquisition cardis used in conjunction with a customized program. !5