Installation for studying the mechanisms of CO2 transformation in the “Soil-Plants-Atmosphere” system

A qualitative study of greenhouse carbon dioxide transformation in the soil-plant-atmosphere system requires appropriate tools to make ecosystem models, record the occurring transformations, and process the obtained data. To expand the methodology for studying carbon dioxide flows, the authors developed an installation for studying the mechanisms of CO₂ transformation in the soil-plant-atmosphere system, simulating and ensuring autonomous vital activity of a plant organism with parallel recording and demonstration of the daily dynamics of CO₂ concentration inside a completely closed system. For a more detailed assessment of carbon dioxide transformation, the installation ensures complete isolation of the leaf and underground parts of plants. A foxglove tree (Paulownia) seedling weighing 7.47 g was used to test the installation; its formed roots were immersed in river sand enriched with a solution of nitroammophoska ( NPK 16:16:16). For 30 days, the iMK LoRa measuring system recorded the absorption and emission of CO₂ in two zones of the installation every 5 minutes. The model experiment showed that the plant is able to continue its development and growth in the absence of an external source of carbon dioxide, and biomass (+111.8%) is formed due to the mechanism of root carbon nutrition. In this case, soil carbon partially (76.4%) goes into the atmosphere as a result of plant respiration and is again absorbed in the light phase, thereby providing a “small carbon cycle”. Another part of the soil carbon (23.6%) takes direct part in the formation of plant biomass, bypassing the transformation through foliation. The proposed installation can identify the features of carbon nutrition modes of various agricultural crops for further selection of means and agrotechnical methods for biomass regulation.

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