Edaphic Atmosphere

The edaphic atmosphere can be defined as the mixture of gases occupying soil macropores. Its composition is very similar to that of atmospheric air, but varies in its different percentages.

The following table compares the different percentages of the gas mixture.

The soil atmosphere is subject to a continuous exchange with external air.This exchange takes place by mass movement (governed by changes in temperature and pressure), such as wind blowing air into the soil or irrigation blowing air out, or by diffusion mechanisms, where it depends on the type of gas and the porosity of the soil.

Diffusion mechanisms involving gas movement in the substrate depend on the type of gas and the porosity of the soil.

The most striking changes occur in relation to Oxygen and Carbon Dioxide. Ehe CO₂ produced in the soil is due to either root respiration or microbial decomposition of organic matter labile (Hanson et al., 2000).

Cellular respiration is a series of reactions by which the cell breaks down organic molecules and produces energy..

Increases in CO₂ up to values of 5 % by volume have been found to be particularly frequent on golf courses, probably as an effect of the high densities of

grasses that occur with the new varieties, intense irrigation and fertilisation.

In all profiles of different soils, CO₂ gradients towards the surface indicate considerable CO₂ losses to the atmosphere (Bolin et al., 1979).

A real example is presented below, where the % volumetric Oxygen measurement probes of the Tiloom sensors were implemented in the soil gas mixture, see attached graph with the correlation with the continuously measured temperatures for the golf course studied.