Carbon dioxide concentrations in soil are higher than in the atmosphere because of respiration of the plants, their roots. Also, CO2 is inhigherr concentration because of the decomposition of organic matter. Decomposition of organic matter produce more CO2 because of increased microbial activity. CO2 concentrations can change as a result of temperature change or different soil structure. Composition of air in soil and atmosphere of CO2 is
Soil Air: 0.25% Atmosphere: 0.04%.