SOIL ORDERS Flashcards
The most extensive soil which covers approx 18% of the Earth’s ice-free land, and is also called young soil but with less horizon development.
Entisols
They are more developed than Entisols, but lack features of other soils. Can also be refered to as young soil, which makes up 15% of the Earth’s ice-free soil.
Inceptisols
Also known as grassland soil. They are characterized by a thick, dark, surface horizon and are used for agricultural purposes.
Mollisols
Are very high-weathered soils found in intertropical regions of the world. Rich in Iron and Aluminum oxide minerals which have low native fertility.
Oxisols
Often refered to as ‘acidic soil’, they are naturally infertile and requires lime in order to be used agriculturally.
Spodosols
Also called the old soil, it is a strongly leached forest soils with low native fertility found in humid, temperate, and tropical areas, typically on older stable landscapes.
Ultisols
Clay-rich soils which are used in rice paddies. They shrink and swell quickly due to the high clay content. They occupy 2-4% of the Earth’s ice-free regions.
Vertisols
Moderately leached soil, with high native fertility.This is known as ‘forest soil’ which makes it productive for both silvicultural and agricultural uses.
Alfisols
Also known as the ‘volcanic soil’; they are formed under volcanic ash and other volcanic ejecta. They are the least extensive of all soil orders with approx. 1% of the Earth’s ice-free soils.
Andisols
Known as ‘dessert soils’, they are characterized by being dry most of the year and limited leaching. They are not used for agriculture unless there is irrigation.
Aridisols
Soils from very cold climates and only consist 0.4% of the world’s population. Low temperatures cause slower decomposition of organic matter.
Gelisols
These soils are mainly composed of organic matter. They contain 30-40% organic matter, they are often referred to as peats or mucks, which restricts them to be used for engineering projects.
Histosols
