Controlling the depth of cultivation and sowing equipment is difficult when moving alternately from wet to dry soil. The wind erosion risk is increased by the forced delay in sowing as well as by dry soil patches and poor cover. Fertiliser placed in the hollows could be subject to increased leaching, while fertiliser in dry soil is less available. Heavy rain in summer or autumn can result in significant runoff and erosion on repellent soils on sloping sites. Rills and gullies have been observed on soils which would have negligible runoff if they were not repellent.
Water erosion can occur on both crop and pasture paddocks.
Advantages of water repellency Not all the consequences of water repellency are necessarily unfavourable and some native plants may induce water repellence to give them a competitive advantage in a harsh environment. Water repellence can reduce moisture loss through evaporation by the 'dry mulch' effect of the repellent surface layers. It can also increase the amount of subsoil moisture by diversion flow from the surface through preferential pathways beneath surface hollows and along plant roots. However, there are also possible disadvantages of diversion flow, due to the faster transport of nutrients and toxins into water supplies. Hydrophobic organic matter Particles of organic matter seem to act as a highly hydrophobic soil component and as a carrier and reservoir of waxes.