Vol. 11, Issue 12 (2022)

Author(s):
RM Muchhadiya, PD Kumawat, HL Sakarvadia and PM Muchhadiya

Abstract:
Carbon dioxide (CO₂) is an important heat-trapping/greenhouse gas that comes from the extraction and burning of fossil fuels (such as coal, oil and natural gas), wildfires and natural processes like volcanic eruptions. A higher concentration of atmospheric CO₂ above the ambient is called elevated CO₂. Open top chamber (OTC) and free air CO₂ enrichment (FACE) technology are used to elevate the atmospheric concentration of CO₂. A change in atmospheric CO₂ could affect soil carbon storage through changes in plant and microbial activities. Elevated atmospheric CO₂ consistently stimulates plant growth, thereby increasing inputs of carbon into soil, mainly through increased detrital production and root exudation. Most of the additional carbon released into the soil in response to elevated CO₂ is labile and decomposes quickly. Accelerated decomposition of soil organic matter by stimulated microbial activity as a result of the higher addition of easily degradable root exudates in response to elevated CO₂ conditions, is termed the priming effect. Elevated CO₂ increases the yield of C₃ plants and also increases the labile pool in the soil, but reduces the old organic carbon pools due to the priming effect. Moisture content at field capacity and moderate temperature (35 ^°C) along with elevated CO₂ (up to 650 ppm) increase soil organic carbon. The SRI method of rice cultivation followed by raised bed wheat cultivation increases total soil organic carbon. Soil carbon sequestration under elevated CO₂ can only be increased when additional nutrients are supplied.