Geoscience Reference
In-Depth Information
pressures on the soils of other regions, thus
increasing the likelihood of soil degradation there.
The second set of pollution processes that are
associated with soils result from the deliberate
application of pesticides and fertilizers to soils.
Arguably the most infamous example of soil
pollution resulting from the application of
pesticides is the case of DDT. During the post-war
period, DDT was a popular agricultural chemical
that was used to control insects that would attack
crops. Over time it was realized that DDT was
having a harmful affect on the ecosystems within
which it was being applied. In a famous book
entitled
Silent Spring
, the American biologist
Rachel Carson (1962) documented how once
DDT had entered the environment through soils
it was being rapidly transferred to plants and
animals. As a so-called persistent organic pollutant
(POP), DDT built up in the tissues of the wildlife
that lived in the areas where the chemical was being
applied. This chemical build-up resulted in a range
of ailments that decimated local bird populations
(among other species) and resulted in springs that
were eerily silent due to the absence of birdsong.
Environmental problems can also be caused by
the excessive application of artificial fertilizers
to soils. As we have mentioned already, the
application of artificial nitrogen and phosphorous-
based fertilizers has enabled agriculturalists to
greatly enhance the productive capacity of soils,
and, at times, prevent soil degradation. But as levels
of artificial fertilizer use have increased, it has
become increasingly common for excess nitrogen
and phosphorous compounds to be transferred
Source: Wikimedia Creative Commons, NASA
