Construction of a Light Emitting Diode Chamber for Measurement of Gas Exchange in the Plant Ecosystem

Abstract

<p><strong>Abstract: </strong>A canopy chamber system is useful to measure gas exchanges in the plant ecosystem. A transparent chamber has been generally used to measure canopy fluxes in the field, such that the light source for photosynthesis depends on the solar radiation. However, it is challenging to measure stable canopy fluxes in the field due to changeable solar radiation conditions in nature. In this study, we constructed a new chamber system to measure canopy fluxes using a Light Emitting Diode (LED) as a light source. Upon the construction, we aim to measure quantitative gas exchanges to estimate the amount of photosynthesis and evapotranspiration using the constructed chamber system in crop fields. While diverse chamber systems have been developed to measure canopy gas exchanges so far, no attempt has been made to create such an LED chamber system according to our best knowledge. The new chamber system was composed of a chamber, LEDs with a maximum power capacity of 1,800W, a water pump for cooling, and a gas analyzer (LI-850, LI-COR, USA). This LED chamber system can estimate the amount of photosynthesis and evapotranspiration rate of plants by measuring both CO<sub>2</sub> and H<sub>2</sub>O fluxes in the ecosystem. These measurements can contribute to the practical assessment of crop productivity as well as scientific advancement in plant ecophysiology.</p><p> </p><p><strong>Keywords</strong>: Crop, evapotranspiration, gas exchange, LED, chamber, photosynthesis</p><p> </p><p><strong>Acknowledgement</strong>: This research was supported by "Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ013841022018)" from Rural Development Administration, Republic of Korea.</p>