Macropore

Macropore

Discussion
Ask a question about 'Macropore'
Start a new discussion about 'Macropore'
Answer questions from other users
Full Discussion Forum
 
Encyclopedia
In soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

, macropores
Characterisation of pore space in soil
Soil is essential to most animals on the earth. It is a relatively thin crust where an even smaller portion contains much of the biological activity. Soil consists of three different phases. A solid phase that contains mainly minerals of varying sizes as well as organic compounds. The rest is pore...

are defined as cavities that are larger than 75 μm. Functionally, pores
Pore
- Animal biology and microbiology :* Sweat pore, an anatomical structure of the skin of humans used for secretion of sweat* Canal pore, an anatomical structure that is part of the lateral line sense system of some aquatic organisms...

 of this size host preferential soil solution
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 flow and rapid transport of solutes
Solute
Solute may refer to:* Solute, UMIK or UBOOK desolving in a substance,forming INT/INTY* Solute , a group of Paleozoic echinoderms...

 and colloids
Colloid
A colloid is a substance microscopically dispersed evenly throughout another substance.A colloidal system consists of two separate phases: a dispersed phase and a continuous phase . A colloidal system may be solid, liquid, or gaseous.Many familiar substances are colloids, as shown in the chart below...

. Macropores increase the hydraulic conductivity
Hydraulic conductivity
Hydraulic conductivity, symbolically represented as K, is a property of vascular plants, soil or rock, that describes the ease with which water can move through pore spaces or fractures. It depends on the intrinsic permeability of the material and on the degree of saturation...

 of soil, allowing water to infiltrate
Infiltration (hydrology)
Infiltration is the process by which water on the ground surface enters the soil. Infiltration rate in soil science is a measure of the rate at which soil is able to absorb rainfall or irrigation. It is measured in inches per hour or millimeters per hour. The rate decreases as the soil becomes...

 and drain
Drainage
Drainage is the natural or artificial removal of surface and sub-surface water from an area. Many agricultural soils need drainage to improve production or to manage water supplies.-Early history:...

 quickly, and shallow groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...

 to move relatively rapidly via lateral flow. In soil, macropores are created by plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

 root
Root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...

s, soil cracks, soil fauna, and by aggregation of soil particles into ped
Ped
A ped is a soil particle.There are five major classes of structure seen in soils: platy, prismatic, columnar, granular, and blocky. There are also structureless conditions. Some soils have simple structure, each unit being an entity without component smaller units...

s.

Macropores may be defined differently in other contexts. For example, in the context of porous solids
Solid
Solid is one of the three classical states of matter . It is characterized by structural rigidity and resistance to changes of shape or volume. Unlike a liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a...

 (i.e., not porous aggregations such as soil), colloid
Colloid
A colloid is a substance microscopically dispersed evenly throughout another substance.A colloidal system consists of two separate phases: a dispersed phase and a continuous phase . A colloidal system may be solid, liquid, or gaseous.Many familiar substances are colloids, as shown in the chart below...

and surface chemists define macropores as cavities that are larger than 50 nm.