Environmental Engineering Reference
In-Depth Information
podzolization. Intense weathering and leaching give rise to laterization. Poor drainage
gives gley soils, which, in arid and sem-arid climates, become saline and alkaline
soils.
2
The soil formed under the prevailing climate and vegetation conditions is the zonal soil.
This corresponds to the climax vegetation and will be found on flat, well drained sites.
In the real world, however, this zonal profile will be considerably modified by local
factors (drainage, limestone rocks), by topography (giving soil hydrologic sequences
or soil catenas) and by the age factor (the length of time particular processes have been
operating).
3
The concept of soil zonality was developed in the late nineteenth century but is still
relevant today as it fits neatly into ecological concepts of biomes and ecosystems. An
understanding of soil-forming processes is vital for a thorough understanding of the
potential of the world's soils for agriculture and forestry.
