What is plinthite formation?
Plinthite formation occurs in conjunction with Btx horizon degradation and in a zone of Fe-accumulation having a firm to very firm consistency. PLINTHITE is an iron-rich, humus-poor mixture of clay with fine quartz. The segregation of Fe is important to the understanding of plinthite-bearing soils.
What is Fragipan soil?
In Soil Taxonomy (Soil Survey Staff, 2010) a fragipan (from the Latin fragilis, meaning “brittle”) is defined as a layer that is 15 cm or more thick, contains a very coarse prismatic, columnar, or blocky structure (or is massive), has a firm or firmer rupture-resistance class (brittle) in more than 60% of its volume.
What is a CR soil horizon?
Cr—mineral horizons or layers of weathered bedrock and saprolite such as granite or partly consolidated soft bed- rock such as sandstone, siltstone or shale with bulk density or consolidation such that roots cannot enter.
What are Plinthic soils?
Plinthite (Gr. plinthos, brick) is an iron-rich, humus-poor mixture of clay with quartz and other highly weathered minerals. It commonly occurs as reddish redox concentrations in a layer that has a polygonal (irregular), platy (lenticular), or reticulate (blocky) pattern.
What is the meaning of vertisols?
Vertisols (from Latin verto, “turn”) are clay-rich soils that shrink and swell with changes in moisture content. During dry periods, the soil volume shrinks and deep wide cracks form.
What is hardpan soil?
Hardpan soil is a soil that is underlaid by a rock-hard layer of material close enough to the surface to limit the depth plants can extend their roots and to prevent internal drainage of the soil. The soil above the hardpan varies in depth from a few inches to two or three feet.
What makes a soil hydric?
The definition of a hydric soil is a soil that formed under conditions of saturation, flooding or ponding long enough during the growing season to develop anaerobic conditions in the upper part.
What is the O horizon called?
humus
The horizons are: O (humus or organic): Mostly organic matter such as decomposing leaves. The O horizon is thin in some soils, thick in others, and not present at all in others.
What is Mispah soil?
The Mispah soil form is characterised by an Orthic A – horizon overlying hard rock. Mispah soil is horizontally orientated, hard, fractured sediments which do not have distinct vertical channels containing soil material. There is usually a red or yellow-brown apedal horizon with very low organic matter content.
What is a vertic soil?
Vertisolic soils are found on parent materials high in clay (i.e., greater than 60 % clay) throughout the Prairie Ecozone and also have a very limited extent in other regions of Canada.
What makes a plinthite hard in a field?
Plinthite is firm or very firm when the soil moisture content is near field capacity and hard when the moisture content is below the permanent wilting point. Plinthite concretions are coherent enough to be separated readily from the surrounding soil. Plinthite commonly occurs within and above reticulately mottled horizons.
What kind of soil is a plinthite made of?
Plinthite is a redoximorphic feature in highly weathered soil. The product of pedogenesis, it commonly occurs as dark red redox concretions that usually form platy, polygonal, or reticulate patterns.
Where does the iron in plinthite come from?
Generally, plinthite forms in a soil horizon that is saturated with water for some time during the year. Initially, iron is normally segregated in the form of soft, more or less clayey, red or dark red redox concretions.
Can a spade be used to cut plinthite?
In a moist soil, plinthite is soft enough to be cut with a spade. After irreversible hardening, it is no longer considered plinthite but is called ironstone. Indurated ironstone materials can be broken or shattered with a spade but cannot be dispersed if one shakes them in water with a dispersing agent.
