Soils of the - Agriculture and Agri-Food Canada

unoff : The portion of the total precipitation on an area that flows away through stream channels . Surface runoff
does not enter the soil . Groundwater runoff or seepage flow from groundwater enters the soil befor e
reaching the stream .
saline : A nonalkali soil that contains enough soluble salts to interfere with the growth of most crop plants . Th e
conductivity of the saturation extract is greater than 4 mmhos/cm, the exchangeable-sodium percentag e
is less than 15, and the pH is usually less than 8 .5
Sand : (i) A soil particle between 0.05 and 2 .0 mm in diameter. (ii) Any one of five soil separates : very
coarse sand, coarse sand, medium sand, fine sand, or very fine sand . (iii) A soil textural class .
sandy : Containing a large amount of sand . It may be applied to any one of the soil classes that contains a larg e
percentage of sand .
science, soil : The science dealing with soil as a natural resource . It includes : soil formation, classification, an d
mapping ; the physical, chemical, and biological properties of soils ; and the management of soils fo r
various purposes such as the production of agricultural and forest crops, the construction of roads, an d
others .
sedimentary rock : A rock formed from materials deposited from suspension or precipitated from solution an d
usually more or less consolidated . The principal sedimentary rocks are sandstones, shales, limestones ,
and conglomerates .
seepage : (i) The escape of water downward through the soil . (ii) The emergence of water from the soil along a n
extensive line of surface in contrast to a spring where the water emerges from a local spot .
series, soil : A category in the Canadian system of soil classification . This is the basic unit of soil classification ,
and consists of soils that are essentially alike in all major profile characteristics except the texture of th e
surface .
silt : (i) A soil separate consisting of particles between 0 .05 and 0 .002 mm in equivalent diameter. (ii) A soi l
textural class .
single-grain structure : A soil structure in which the soil particles occur almost completely as individual o r
primary particles ; secondary particles or aggregates are seldom present . It is usually found only in very
coarse-textured soils .
soil : (i) The unconsolidated material on the immediate surface of the earth that serves as a natural medium fo r
the growth of land plants . (ii) The naturally occurring unconsolidated material on the surface of the eart h
that has been influenced by parent material, climate (including the effects of moisture and temperature) ,
macro- and micro-organisms, and relief, all acting over a period of time to produce soil that may differ fro m
the material from which it was derived in many physical, chemical, mineralogical, biological, and morphological
properties . (iii) For the purpôse of the Canadian taxonomic system, the earth's surface (th e
material that is to be classified) is divided into soil and nonsoil . Soil is the naturally occurring, unconsolidated,
mineral or organic material at the earth's surface that is capable of supporting plant growth . I t
extends from the surface to 15 cm below the depth at which properties produced by soil-formin g
processes can be detected . These properties differ from those found in any underlying unconsolidate d
material .
soil forming factors : The variable, usually interrelated natural agencies that are responsible for the formatio n
of soil . The factors are : parent material, climate, organisms, relief, and time .
solum : (see Genesis, soil) .
stones : Rock fragments greater than 25 cm in diameter if rounded and greater than 38 cm along the greate r
axis if flat . In engineering practice these fragments are included with boulders, which are considered to b e
greater than 20 cm in diameter.
stoniness : The relative proportion of stories in or on the soil .
stony : Containing sufficient stones to interfere with or prevent tillage . To be classified as stony, more than 0 .1 %
of the surface of the soil must be occupied by stones .
structure, soil : The combination or arrangement of primary soil particles into secondary particles, units, o r
peds. The peds are characterized and classified on the basis of size, shape, and degree of distinctnes s
into classes, types, and grades .
subgroup, soil : A category in the Canadian classification system . These are subdivisions of the soil grea t
groups .
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