Studies on the Carbon dioxide Factor in the Air and Soil Layers near the ground

Abstract

The paper deals with the study of CO2 content of the air layers with which the plants are primarily concerned. It describes variation of the atmospheric and soil air CO₂ with (i) height/depth (ii) time of day and (iii) season. The study was made In the open as well as within crops. The effect of irrigation on CO2-content of the soil air is also described. Pettenkoffer's method of CO2-absorptlon by biota and subsequent titration by oxalic acid using phenolphthalein as indicator was used for CO2-estimation. The samples of soil air from within the soil were drawn out for CO2-estimation through a specially designed steel probe. For the duration of this study the average value of CO₂ concentration In the air layers within the first eight feet above the ground surface was 0.0490;0 and that In the soil air under a bareplot at a depth of 35 cm. was 0.13%,

The study indicates that the amount of CO2 In the air IS more Inside a crop than In the open, (ii) it is more during night than during the day-the minimum being in the afternoon and (iii) it is more during winter than during summer, the minimum being in the rainy season CO2-content. does not appear to vary with height upto the first 35 feet above the ground surface. Soil air CO2 Increases In concentration with depth. It is more under a crop-field than under a bare, plot. Its maximum concentration occurs In the rainy season and minimum early In spring and the low values continue throughout the summer months. The effect of irrigation appears to increase the concentration of CO2 in the soil air.