2.3 Field warming treatment
In order to realistically simulate the global warming scene, we have
conducted elevated temperature experiment since 2009 through the FATE
(free-air temperature enhancement) system in the rice field (Rehmani et
al., 2011&2014; Dou et al., 2018; Tang et al., 2019). Warming treatment
was performed by FATE with 12 ceramic infrared radiator heaters
(FTE-1000-240-0-L10-Y; 1000W, 240V; 245 mm long × 60 mm wide) 1.2m above
the rice canopy in each experimental plot. Angles of the heater in the
horizontal and vertical directions are 45° and 30° to ensure the
consistent and stable heating of the canopy and the effective area of
infrared radiation is 1.5 × 1.5 × 3.1416 = 7.1m2,
respectively (Figure 1). Two sensors (Model HOBO U23-001) were installed
and located at the canopy height in each plot to record the temperature
and humidity changes of rice canopy. The HOBO was set to record the data
every 30 minutes, and HOBO Pro software was used for data processing.
Field meteorological data during the test period were collected from the
meteorological station (WatchDog 550) installed ~100 m
away from the experimental field (Tang et al., 2019). Daytime and
nighttime of rice canopy temperature were increased by 1.568 ℃ and 3.089
℃, respectively (Supplemental figure 1). Temperature increase range and
trend were in accordance with the temperature range of global warming
and the rule of asymmetric warming characteristics.