Compaction and water saturation of soils are the main barriers to soil oxygen transport, water being a more effective barrier (Papendick and Runkles, 1965; Moldrup et al., 2000a; Neale et al., 2000). The diffusion of gases in water is slower than their diffusion in air by a factor of 10⁴ (Call, 1957; Moldrup et al., 2000a; 2004; Thorbjorn et al., 2008).
Suzanne DeJohn (2017) summarizes this problem adequately "Soil that’s too wet can also cause wilting, as excess water pushes air out of the soil and suffocates the roots." Plants need oxygen to absorb water and nutrients from the soil. Waterlogged soil essentially "drowns" the root-zone, impeding the biological and chemical processes necessary for healthy plant growth and crop production.
As indicated above, irrigation scheduling reduces waterlogging problems, therefore assisting with soil aeration by minimizing the most significant barrier to soil oxygen transport i.e. too much water.