Environmental Engineering Reference
In-Depth Information
ecosystem provides great support, working every minute of the day in each cubic
centimetre of the soil. And the impressive work of the soil ecosystem in improving
soil quality does not cost anything. Moreover, soil organisms will create a natu-
ral equilibrium, while human beings are forced to constantly keep up their soil
management. Therefore, the soil ecosystem is to be treated with great respect in
sustainable agriculture. This generally requires a focus on a fruitful co-operation
between men, accepting a minimal role, and soil organisms. Most soils left alone
will develop at least an acceptable soil structure 'on their own'. As an example,
strategic and applied research has demonstrated that certain co-operative micro-
bial activities can be exploited, as a low-input biotechnology, to help sustainable,
environmentally-friendly, agro-technological practices (Barea et al.
2005
).
13.8.4 Improving Sustainability
An important pillar of sustainability relates to the resilience and restoration of the
soil ecosystem. Here, Ecological Risk Management offers possibilities. Ecosystem
Services should be used as often as possible, instead of using artificial tools for
soil management. Optimal conditions for Ecosystem Services, therefore, should be
maintained or created, also in regard to the presence of contaminants. A good exam-
ple of a sustainable process in soil is the repeated cycling of the same nutrients in soil
by organisms: first, soil dwelling organisms release immobile minerals and convert
them into nutrients that are available to plants. Then, when the plants die, organisms
will decay the plant material and, subsequently, recycle the nutrients. In principle,
this recycling will continue indefinitely and the soil organisms will be responsible
for plant nutrition without any human interference.
13.9 Monitoring the Soil Ecosystem Quality
13.9.1 Indicators
Monitoring
is the repetitive measurement on the same place in order to determine
trends over time. Monitoring the quality of the soil ecosystem requires insight into
the soil processes and the development of indicators. Ecological quality depends
on chemical, physical, and biological characteristics of the soil. Chemical moni-
toring of soil is often performed in terms of measurements of the concentration
of contaminants. In soil science, there is a good understanding about the physical
characteristics of the soil, including soil type, bearing capacity, groundwater lev-
els and so on. Not so much is known about soil biology. Many indicators exist for
sub-cellular and cellular species, population and at the community level. However,
application of these indicators, measurement of biological entities in a monitoring
system, does not occur very often. Avidano et al. (
2006
) used functional (sub-
strate utilization pattern and enzymatic activities of the soil extracts) and structural
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