Estimating Rice Panicle Temperature with Three-Layer Model. (20th March 2020)

• Record Type: Journal Article
• Authors: Wang, Yanyan; Oue, Hiroki; Luo, Zhijun; Chen, Ming; Liu, Shiyu; Zhou, Chunhuo; He, Xiaowu
• Other Names: Hashiguchi Hiroyuki Academic Editor.
• Is Part Of: Advances in meteorology. Volume 2020(2020)
• Publication Date: 2020-03-20
• Subjects: Meteorology -- Periodicals; Meteorology; Periodicals; 551.505
• DOI: 10.1155/2020/6468909
• Languages: English
• ISSNs: 1687-9309

Abstract

Abstract : Rice panicle temperature ( T p ) is a key factor for studying high temperature impacts on spikelet sterility. Comparing with measuring T p by hand, a T p simulation model could obtain T p data readily. The two-layer energy budget model which divides the soil layer and canopy layer was widely used to predict rice canopy temperature ( T c ), but panicle existed mostly in the upper layer canopy, and we have proved that T c was different from the upper layer canopy temperature ( T c 1 ), and the upper layer must be separated from the whole canopy for the purpose of estimating T p . Thus, we developed the three-layer model, contained upper canopy layer with panicle (50–100 cm), lower rice canopy layer (10–40 cm), and water surface layer (≤10 cm) to estimate T p with general meteorological and vegetation growth data. There were two steps to estimate T p . The first step was calculating T c 1 and lower layer canopy temperature ( T c 2 ) by solving heat balance equations with canopy resistances. And the second step was estimating T p with following parameters: (a) the inclination factors of leaves and panicles ( F 1, F 2, and F p ) which were decided by fitting the calculated transmissivity of downward solar radiation (TDSR) to the measured TDSR, (b) the aerodynamic resistance between the panicle and atmosphere ( r ap ) denoted by wind speed, (c) the panicle resistance for transpiration ( r p ) denoted by days after heading, and (d) air temperature and humidity at the panicle's height ( T ac 1 and e ac 1 ) calculated from the resistances of the pathways of sensible and latent heat fluxes in accordance with Ohm's law. The model simulated fairly well the T c 1, T c 2, and T p with root mean square errors (RMSEs) of 0.76°C, 0.75°C, and 0.81°C, respectively, where RMSE of measured T p and predicted T p by integrated micrometeorology model for panicle and canopy temperature (IM 2 PACT) including two-layer model was 1.27°C. This model was validated well by two other rice cultivars, and thus, it demonstrated the three-layer model was a new feasible way to estimate T p .