When rain, wind or frost detach soil particles from the surface, the particles are washed or blown off the paddock.Sheet erosionThis occurs when rain falls on bare or sparsely covered soil, loosening fine particles (silt, clay and humus) that are carried downhill in surface run-off. Sheet erosion lowers the fertility of the soil, because it removes the most productive layer, which has usually been enriched by fertiliser.Wind erosionThe wind can remove the valuable fine soil on the land surface. Seasonally strong winds hit many areas, such as sand dunes, the Central Volcanic Plateau, Wairarapa, Hawke’s Bay, Canterbury and Otago. If covering vegetation has been grazed or disturbed, wind erosion can be severe.
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