An Acrisol is a Reference Soil Group of the World Reference Base for Soil Resources (WRB). [1] . It has a clay-rich subsoil. It is associated with humid, tropical climates, such as those found in Brazil, and often supports forested areas. [2] .

Acrisols are defined by the presence of a subsurface layer of accumulated kaolinitic clays where less than half of the ions available to plants are calcium, magnesium, sodium, or potassium and also by the lack of an extensively leached layer below the surface horizon (uppermost layer).

Acrisols are found on acid rocks, mostly of Pleistocene age or older. They are most extensive in South-east Asia, the southern fringes of the Amazon Basin, the southeastern USA and in both east and west Africa. There are approximately 1000 million hectares of …

Acrisols world-wide. Associations with other Reference Soil Groups. Acrisols are often the dominant soil group on old erosional or depositional surfaces and in piedmont areas in humic tropical regions where they are associated and alternating with Nitisols, Ferralsols and Lixisols.

Under the modified legend this class consists only of clays with low cation exchange capacity. Haplic Acrisols, added to the revised legend. Orthic Acrisols, deleted in the revised legend. A new soil class of formerly Acrisols with clays with high cation exchange capacity.

With proper land use and management systems, both Acrisols and Alisols can be highly productive and sustainable. Soils with clay-enriched subsoil horizon are widespread worldwide. The presence of a distinct red-brown and/or yellow color in Luvisols and Alisols/Acrisols underlines the importance of pedogenic iron oxides in them.

2016年1月1日 · Acrisols are characterized by the presence of an ochric or an umbric A horizon (10 to 30 cm depth), overlying an argic Bt horizon, which is deep, generally intensively colored (either yellow or brown to red), and whose structure ranges between prismatic, blocky, or granular, although in some cases, and under certain conditions, it can have a ...

Rolling to hilly landscape in southeast China with a Cambisol (steeper parts) - Acrisol (more sloping parts) soil association.

Acrisols are highly weathered soils occurring in warm temperate regions and the wetter parts of the tropics and subtropics. Acrisols develop mostly on old land surfaces with hilly or undulating topography with a natural vegetation type of a light forest.

2025年1月9日 · Learn about the definitions, characteristics, diagnostic criteria, and classification of Acrisols, Alisols, Lixisols, and Nitisols. Explore their distribution, associated soils, and genesis factors. This comprehensive lecture delves into the intricacies of these important soil types.