Preface
There has been increasing interest in our environments, which consists mainly of air,
water, and soil environments. Organisms, including humans, live within and interact
with these environments. However, the degree of the interest about soil has not been
as high as those for air, water, and organisms because air pollution, changes of air
temperature, contamination of water, flooding, shortages of water, and increases and
decreases in the abundance and diversity of organisms tend to affect us more
directly. Changes in soil are less conspicuous because soil has buffering capabilities,
to some extent, against various impacts.
The buffering actions of soils, which are an outstanding aspect of soil, are due to
the sorption and release of various materials by soil constituents and to biological
activities. For example, the buffering action of soil against acids and bases is
primarily due to the surface properties of inorganic and organic constituents.
In addition, the biological buffering action of submerged soils can result in the
reduction of nitrogen oxides and sulfur oxides added to soils by acid deposition.
Soil may appear very typical or similar when considering only the familiar
surface of soil. However, once one has an opportunity to observe a different soil,
he or she may become interested in the soil because of its unique aspects. To find a
different soil, one needs only to visit a place with a different landscape or dig into
soil to a depth of 0.5–1 m. Different soils often exist beneath different landscapes,
and as many soils show differentiation into various horizons, there may be differently colored horizons beneath the surface of the soil. These observations lead to
questions about the reasons for the differences between typical soil and the newly
found soil.
One answer to these questions is the difference in soil constituents between
various soils. Soil inorganic constituents are related to brown, red, yellow, black,
and white colors of soils, whereas soil organic constituents are related to dark or
dark-brown colors. Redox reactions of soil inorganic constituents are also related to
blue color and brown mottling in soils. The feel and consistence of soils also depend
on the properties and composition of soil constituents.
v
There has been increasing interest in our environments, which consists mainly of air,
water, and soil environments. Organisms, including humans, live within and interact
with these environments. However, the degree of the interest about soil has not been
as high as those for air, water, and organisms because air pollution, changes of air
temperature, contamination of water, flooding, shortages of water, and increases and
decreases in the abundance and diversity of organisms tend to affect us more
directly. Changes in soil are less conspicuous because soil has buffering capabilities,
to some extent, against various impacts.
The buffering actions of soils, which are an outstanding aspect of soil, are due to
the sorption and release of various materials by soil constituents and to biological
activities. For example, the buffering action of soil against acids and bases is
primarily due to the surface properties of inorganic and organic constituents.
In addition, the biological buffering action of submerged soils can result in the
reduction of nitrogen oxides and sulfur oxides added to soils by acid deposition.
Soil may appear very typical or similar when considering only the familiar
surface of soil. However, once one has an opportunity to observe a different soil,
he or she may become interested in the soil because of its unique aspects. To find a
different soil, one needs only to visit a place with a different landscape or dig into
soil to a depth of 0.5–1 m. Different soils often exist beneath different landscapes,
and as many soils show differentiation into various horizons, there may be differently colored horizons beneath the surface of the soil. These observations lead to
questions about the reasons for the differences between typical soil and the newly
found soil.
One answer to these questions is the difference in soil constituents between
various soils. Soil inorganic constituents are related to brown, red, yellow, black,
and white colors of soils, whereas soil organic constituents are related to dark or
dark-brown colors. Redox reactions of soil inorganic constituents are also related to
blue color and brown mottling in soils. The feel and consistence of soils also depend
on the properties and composition of soil constituents.
v