Environmental Engineering Reference
In-Depth Information
Modeling of the emissions based on C, N, and P mass balances is an effective method
to compare manure management methods. However, soil conditions, climate, and other
factors can signiicantly inluence the results of the comparison. This approach is a clear
example of minimization of the impact of agricultural practices shown in Figure 6.12.
6.6 Tools for Evaluation of Geoenviroment Impacts
from Farming Stressor Sources
6.6.1 Agricultural Sustainability
To avoid and/or mitigate risks and protect soil quality and geoenvironmental quality as
a whole, we need to develop a methodology for evaluation of potential and existing risks
to agricultural and geoenvironment sustainability as a result of agricultural activities.
It has been estimated that 28% of soil degradation is due to faulty agricultural practices
(Quendler and Reichert, 2002). There appears to be some signiicant room for improve-
ment. One needs to (a) examine the impact of the farming practices on the quality of
groundwater and other receiving waters, soil quality, and biodiversity; (b) seek methods
to quantify the various kinds of emissions that take the form of stressors to the geoen-
vironment; and (c) determine the fate and transport pathways of the harmful emissions
(stressors). By including air, water, soil, and vegetation as part of the agroecosystem, one
could seek measures in an integrated approach to (a) limit the harmful discharges and
(b) curtail ineficient practices or emissions—as the irst major step toward generation
of sustainability. Some of these measures include (a) ecological footprint, (b) sustainable
processing index (SPI), and (c) material intensity per service unit (MIPS) or land intensity
per service unit (LIPS) (Quendler et al., 2002). Models and sustainability indicators are also
tools that can be used to evaluate sustainability. The analysis of sustainability thus will
rely on sustainability indicators, reference values, and an established evaluation method.
A listing of some indicator systems has been reported by the OECD (1996).
Attempts have been made to deine the components of agricultural sustainability. One of
the most inclusive was formulated by Christen (1996) as depicted schematically in Figure
6.13. Ethical considerations include fairness between generations. Resources and biodiver-
sity need to be preserved without reducing production but by minimizing environmental
impact. Economic viability must also be ensured both for small and large enterprise farm-
ing units. Since soil will always be used for agricultural purposes, the impact of pollution
and erosion must be determined through research and ield studies.
Some authors have argued that the deinitions of organic farming (Quendler and Schuh,
2002) should follow the same principles as those used to establish sustainable agriculture.
These principles include
• Working with a closed system to draw on local resources
• Maintaining the fertility of the soil over the long term
• Avoiding all forms of pollution
• Producing high nutritional quality food in suficient quantities
• Reducing the use of fossil fuels to a minimum
• Giving livestock humane conditions
Search WWH ::
Custom Search