A peculiar trait of these soils is that they are easily moved by the wind: the vegetation has shallow roots,that can be further loosened by a dry spell or excessive grazing. The strong winds that blow in these tree-less areas lift the materials that compose the surface layers, forming violent dust storms. Later on, the soil settles back down, thus creating a layer, the so-called loess, which remarkably and favourably affects farming and the life of some locals. With time, these deposits have formed typical soils, the loess, which are yellow in colour. Today, the loess cover approximately 10% of the lands above sea level; typical are the Chinese loess which seem to derive from the desert of central Asia and are over 100 metres thick in the Huang-Ho basin. The same deposits, even if not as thick, can also be found in Europe and north-America, probably settled during the colder periods of the Pleistocene in steppe and tundra areas.
In loess areas, wheat , maize, millet, cotton and linen are grown, and pigs, muttons, cattle and horses are reared.