It is thought that sandy soils are more likely to have this condition as the particles have a relatively lower surface
area than other soil materials.
Water repellent (or hydrophobic) soils is often a more common problem in sandy soils and potting mixes. In
weather conditions that are dry and windy, soil can dehydrate. Applied water will pool on the surface of the dry
soil rather than wetting it – and will then either evaporate or run off. Once this occurs the soil can be difficult to
The breakdown of organic matter causes water repellent issues, but it is the type of organic matter
rather than the total soil carbon that creates water repellency.
When soil moisture reaches a critical level water repellency can be overcome. It should be noted though that
critical levels are different for different soils and it takes longer for water to infiltrate soils that are hydrophobic.
It is difficult to prevent water repellency as it is a natural condition of soils. Adding organic composts and
mulching can assist as a preventative measure.