It's called hydrophobic soil. There are a number of things that can contribute to it but the bottom line is the soil is dry and lifeless. Without bacteria and fungi to bind particles of sand, silt and clay into aggregates just the polar attraction of particles can make it impenetrable. There can also be a buildup of organic waxes and oils on the particles from plant debris, again without the microbes to degrade them they repel water.
|