Monitoring responses of NDVI and canopy temperature in a rice field to soil water and meteorological conditions

• Published in: IOP conference series. Earth and environmental science 2022-07, Vol.1059 (1), p.12037
• Main Authors: Irsyad, F, Oue, H, Mon, M M
• Format: Article
• Language: English
• Subjects: Aerial photography; Canopies; canopy temperature; Cultivars; Flowering; Moisture content; Monitoring; NDVI; Rice; rice field; Rice fields; Soil conditions; Soil temperature; Soil water; Spatial variations; Temperature measurement; thermal imagery; Unmanned aerial vehicles; Water content
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/1059/1/012037

Aerial photography of the vegetation canopy is an effective approach for spatial monitoring and evaluating physiological plant conditions precisely and accurately. This study aimed to obtain the relationship between the response of NDVI and canopy temperature in the rice field to soil water (before and after the irrigation process) and meteorological variables. This study was conducted in Matsuyama, Japan, with a rice cultivar ( Oryza sativa L. cv. Koshihikari ) and focused on the heading and flowering stage (July 31 - August 10, 2020). Aerial photographs were successfully detected the spatial variation of NDVI and canopy temperature across the rice fields. Taken NDVI by the UAV camera was successfully correlated with the SPAD value at the same point (R 2 = 0.96), and thermal imagery by UAV also successfully correlated with the hand-held temperature measurement at the same point (R 2 =0.84). NDVI values in the wet soil condition of the rice field were higher than those in the dry condition. Moreover, the canopy temperature in the dry area was higher than in the wet area by an average difference of 0.63 °C. The yield with high soil water content was significantly higher (P=0.03) than those in the lower condition by 0.28 kg/m 2 .