Testbed for Studying the Efficiency of Plants Photosynthetic Irradiation Based on Measuring Carbon Dioxide Concentration in the Air

Abstract

The work is devoted to the description of a testbed that allows studying the efficiency of photosynthetic irradiation of plants by measuring the level of carbon dioxide concentration in the air, which in turn determines the intensity of photosynthetic processes in plants. This method makes it possible to significantly increase the speed of comparative research of the effect of irradiation modes on crop yields. The developed testbed is based on the ESP8266 microcontroller with sensors for measuring carbon dioxide concentration, temperature, air humidity, and a microcontroller implementing the control of plant irradiation modes. Measurement of carbon dioxide concentration was carried out using the MH-Z16 sensor, the principle of which is based on the measurement of non-dispersive infrared radiation (NDIR). In the testbed LED irradiators with a continuous emission spectrum and LED irradiators with a combined emission spectrum (white light + “red” radiation) were used. The testbed allowed us to study the dependence of the efficiency of photosynthesis on the conditions of irradiation by varying the spectral composition of radiation, irradiance intensity. The measurement of carbon dioxide concentration in the phytotron showed its significant dependence on the irradiation conditions. Since the rate of change in the concentration of carbon dioxide occurs over a sufficiently long period of time, research into the irradiation efficiency was carried out on the basis of an assessment of the dynamics of carbon dioxide concentration. Another variant of the research was the consistent comparison of changes in the concentration of carbon dioxide under different irradiation conditions.