Li 190r

Photosynthetic active radiation was measured by a light quantum sensor (model Li-190R, Li-Cor Inc., Lincoln, NE, USA), which was installed near the experimental site. The radiation sensor was connected to a data logger (model CR3000 Series), which was used to record incident photosynthetic active radiation every 10 minutes. Daily intercepted photosynthetic active par (Ipar) and accumulated Ipar of plant canopy were calculated as follows:
where I₀ is photosynthetic active radiation retrieved directly from the sensor. $\text{Fipar}$ is the fraction of photosynthetic active radiation, which was substituted by observed canopy coverage in this study. $Aipar$ is accumulated intercepted photosynthetic active radiation, with t as the growth period under consideration.

The experimental design procedures and data analysis for soil water evaporation under SCAPV are described in Supplementary Material S3.
Air-dried loamy soil was procured from Huabiao (Chengdu, China). The soil was dried for 78 hours and then carefully mixed to distribute uniform moisture content. The air-dried soil was then compacted to a depth of 25 cm inside the evaporation containers. The soil-filled evaporation containers were immersed into water with a depth of 10 cm for 48 hours. Subsequently, the evaporation containers were removed from the water tank to discharge gravity water through the bottom holes for 24 hours.⁴⁰ (link) Thereafter, the evaporation containers were weighed and placed in (a) open-air and (b) SCAPV, as in Figure S2. Three replicates were used in each experiment.
Environmental parameters including air temperature, solar radiation, relative humidity, and wind speed are measured by multi factor meteorological stations (RS-QXZ, Renke, China). The absolute spectra from 300 nm to 900 nm and PPFD were measured by micro-spectrometer (Ocean Insight SR2, USA) and Li-190R (LI-COR, USA), respectively. The PPFD of P1, P2, P3 under SCAPV is measured and averaged by Li-190R at multiple points on clear weather.

The light use efficiency (LUE) and transpiration mass flow density caused by both light treatments were measured using two gas exchange systems (BERMONIS, Steinbeis GmbH & Co. KG, Stuttgart, Germany) and recorded all 30 s. Each gas exchange system consisted of 10 leaf chambers. As such, 10 leaf chambers were distributed on five plants of each light treatment. One leaf chamber was attached to the first and one to the second fully developed leaf of each randomly selected plant. Simultaneously, PPFD was measured (Li-190R, LICOR, Lincoln, NE, United States) at each leaf chamber. This was done three times between 8.00 pm and midnight for a period of 1 week, starting on 6 February. LUE is here defined as CO₂ uptake (μmol CO₂ m^–2 s^–1) divided by the incident PPFD (μmol m^–2 s^–1) and expressed as μmol CO₂ μmol^–1 PPFD. The transpiration mass flow density was measured with the same experimental setup using the BERMONIS system and expressed as mg m^–2 s^–1.
Leaf temperatures were measured under both light treatments with thermoelements during five consecutive weeks (starting point 16 weeks after sowing), where mean values were calculated per week. Five thermoelements were fixed on the first fully developed leaf of five different plants.

Light transmission through the biofilm was calculated daily based on the difference between PFD above and below the flow-cell (Eq. 5) measured by the light meter (LI-190/R; LI-COR Biosciences GmbH). $$\begin{array}{c}\hfill Lightattenuation=\frac{I_{\mathit{in}}-I_{\mathit{out}}}{I_{\mathit{in}}}\times 100\%\end{array}$$ where $I_{\mathit{in}}$ refers to incident light on the top of the flow-cell, $I_{\mathit{out}}$ refers to output light through the channel with biofilm (mean of three positions’ outputs along the channel).

Photon flux density was measured using a light meter (LI-190/R; LI-COR Biosciences GmbH, Bad Houmburg, Germany). Light attenuation by the biofilms was monitored by placing the flow-cells on the sensor of the light meter. Light attenuation was measured in three positions along the length of each channel present in the flow-cells. The attenuation of light was expressed with respect to the transmitted light measured before injecting the cells in the flow-cells (at day 0) as follow: $${lightattenuation}_{\left(i\right)}(\%)=1-\frac{{transmittedlight}_{(i)}}{{transmittedlight}_{(0)}}·100$$ where i represents the day during the growth of the biofilms.

Temperature in the growth room was regulated with an industrial ventilation and air-conditioning unit (HBH030A3C20CRS; Heat Controller, LLC., Jackson, MI, United States) connected to a wireless thermostat (Honeywell International, Inc., Morris Plains, NJ, United States). The deep-flow hydroponic system was equipped with two light quantum sensors (LI-190R; LI-COR, Inc., Lincoln, NE, United States), two thermocouples (0.13-mm type E; Omega Engineering, Inc., Stamford, CT, United States), two infrared sensors (OS36-01-K-80F; Omega Engineering, Inc.), a CO₂ transmitter (GMD20; Vaisala, Inc., Louisville, CO, United States), and a relative humidity and temperature probe (HMP110; Vaisala, Inc.). All sensors were connected to a datalogger (CR1000; Campbell Scientific, Inc., Logan, UT, United States) with a multiplexer (AM16/32B; Campbell Scientific, Inc.), which recorded environmental parameters every 10 s and logged hourly averages using computer software (LoggerNet; Campbell Scientific, Inc.). The air temperature, canopy temperature, CO₂ concentration, and relatively humidity throughout the experiment (mean ± standard deviation) were 22.5 ± 1.0°C, 24.1 ± 0.9°C, 392 ± 31 ppm, and 44 ± 8%, respectively.

Blue light curves at different temperatures were carried out on Arabidopsis plants. Plants were dark adapted for 30 min prior to measurements (n = 5 plants). The light response curve consisted of 161 FRRFs_0.75ms. It was one FRRF_0.75ms in the dark-adapted state and 40 FRRFs_0.75ms at each light intensity level in a 1.5 s interval. Light intensities were 80, 100, 200, 400 µmol photons m⁻² s⁻¹. Plants were measured from low to high light intensities at 25°C, 35°C (63 DAS), and the following day at 20, 15, and 30°C (64 DAS). Transition between temperatures took about 20 min. LI-COR sensors were matched at every temperature step and after every second measurement.
The blue LED of the LIFT instrument was used as actinic light source (445 nm). The size of the illumination spot was around 3 cm². The intensity of the blue LED was calibrated by using a quantum sensor (LI-190R, LI-COR, Inc.) at 60 cm distance. A fully expanded leaf was placed into a LI-6400XT transparent 2x3 cm chamber head (LI-COR, Inc., Nebraska USA) and measured with the LIFT instrument through the transparent film of the chamber. The air flow rate during the measurements was 300 µmol air s⁻¹ and block temperature was kept at 20°C. CO₂ concentration in the air was controlled at 400 ppm and air flow was set to 400 µmol s⁻¹.