• Korean Journal of Agricultural and Forest Meteorology
• /
• v.23 no.4
• /
• pp.316-328
• /
• 2021

In this study, the leaf Na content prediction model for spring potato was established using 400-1000 nm hyperspectral sensor to develop the multispectral sensor for the salinity monitoring in reclaimed land. The irrigation conditions were standard, drought, and salinity (2, 4, 8 dS/m), and the irrigation amount was calculated based on the amount of evaporation. The leaves' Na contents were measured 1st and 2nd weeks after starting irrigation in the vegetative, tuber formative, and tuber growing periods, respectively. The reflectance of the leaves was converted from 5 nm to 10 nm, 25 nm, and 50 nm of FWHM (full width at half maximum) based on the 10 nm wavelength intervals. Using the variance importance in projections of partial least square regression(PLSR-VIP), ten band ratios were selected as the variables to predict salinity damage levels with Na content of spring potato leaves. The MLR(Multiple linear regression) models were estimated by removing the band ratios one by one in the order of the lowest weight among the ten band ratios. The performance of models was compared by not only R2, MAPE but also the number of band ratios, optimal FWHM to develop the compact multispectral sensor. It was an advantage to use 25 nm of FWHM to predict the amount of Na in leaves for spring potatoes during the 1st and 2nd weeks vegetative and tuber formative periods and 2 weeks tuber growing periods. The selected bandpass filters were 15 bands and mainly in red and red-edge regions such as 430/440, 490/500, 500/510, 550/560, 570/580, 590/600, 640/650, 650/660, 670/680, 680/690, 690/700, 700/710, 710/720, 720/730, 730/740 nm.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.46 no.2
• /
• pp.62-68
• /
• 2018

This study investigated the effect of light intensity on the removal of particulate matter by Dieffenbachia amoena 'Marianne' and Spathiphyllum spp.. An acrylic chamber ($600{\times}800{\times}1200mm$, $L{\times}W{\times}H$) modeled as an indoor space and a green bio-filter ($495{\times}495{\times}1000mm$, $L{\times}W{\times}H$) as an air purification device were made of acrylic. The removal of particulate matter PM10 and PM1, the photosynthetic rate, stomatal conductance, and number of stomata of Dieffenbachia amoena 'Marianne' and Spathiphyllum spp. were measured according to three different levels of light intensity (0, 30 and $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$). Regarding the length of time taken for PM10 to reach $1{\mu}g$, the Dieffenbachia amoena 'Marianne' showed a significant difference according to the presence or absence of light, and there was no significant difference shown between light intensity of 30 and $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. As for the Spathiphyllum spp., there was no significant difference between 0 and $30{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$, while a significant difference was shown at $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. After 90 minutes, the PM1, PM10, and $CO_2$ residuals of the Spathiphyllum spp. were lowest at $60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. The remaining amount of PM1 and PM10 was lower with the Spathiphyllum spp. than with the Dieffenbachia amoena 'Marianne', even at $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}PPFD$. With both plants, the higher the light intensity, the higher the photosynthetic rate, while the stomatal conductance did not show any significant difference. Spathiphyllum spp. showed a higher photosynthetic rate and stomatal conductance and a greater number of stomata than Dieffenbachia amoena 'Marianne', and stomata were observed in both the front and back sides of the leaves. The air purification effect of Spathiphyllum spp. is considered to be better than Dieffenbachia amoena 'Marianne' at the same light intensity due to such plant characteristics. Therefore, in order to select effective indoor plants for the removal of particulate contamination in an indoor space, the characteristics of plants such as the photosynthetic rate and the number and arrangement of stomata according to indoor light intensity should be considered.